Sudoku: 81 Squares Can’t Be Wrong. The Official Just Another Mobile Monday Sudoku Variation Roundup.

Ever since they started publishing it in the Washington Post, I have been addicted to Sudoku, the quirky Japanese numbers puzzle. If you are not familiar with Sudoku by now, the rules are fairly simple.  Gameplay proceeds on a 9×9 grid, which is further divided into 9, 3×3 squares.  Based upon the numerical clues provided, the object of the game is to fill in the numbers 1-9 in each of the 81 boxes, without repeating a number in any horizontal row, vertical column, or 3×3 square.   I have already looked at the traditional Sudoku game at length, and reviewed two of the best versions available for the Pocket PC, Astraware Sudoku, and Spb Sudoku, which is included in Spb Brain Evolution. 

As a result of the vast popularity of Sudoku, numerous game and puzzle makers have created a mini-industry, stretching the boundaries of traditional Sudoku with complex and difficult variations.  I have scoured the Internet and found nine exceptional interpretations of the Sudoku game. Specifically, and in no particular order, I will be guiding you through a critical inspection of:     

1. Wordoku To Go

2. Head2Head Sudoku

3. Kokonotsu

4. Sudoku GL

5. The Sudoku Collection

6. Solitaire Sudoku

7. ISS Killer Sudoku

8. Sudoku 3D

9. Multi Sudoku II

WORDOKU TO GO

Wordoku To Go, by Puzzle Express, takes the familiar Sudoku format and turns it on its head by using nine-letter sequences instead of numbers.  In a lot of ways, this made it feel like bumping into an ex-girlfriend who has gotten a new hairstyle.  There is a familiar feeling, but it is just different enough that you can’t keep stop staring at her.  

As in the traditional game, you are faced with an 81 block grid.  Unlike the traditional game, however, Wordoku provides you with a list of nine letters on the bottom of the screen.  Instead of numbers, you must input the nine letters into the grid so that each letter appears only once in each row, column, or 3×3 square.  In order to make matters more difficult (or to provide you with an additional clue, depending upon your perspective), the middle horizontal row (shaded gray) will always spell a single nine-letter word. 

I played Wordoku To Go for several weeks before beginning this roundup, and I have to say, using a random group of letters, rather than nine sequential numbers, really does add a whole new dimension to the game.  One of the strategies I use to solve Sudoku puzzles is based upon the cadence of the numbers.  It is easy to quickly run through the numbers 1-9 in sequential order to check your work and determine your next move.  This is considerably more difficult to do when you are dealing with nine (out of a possible 26) seemingly random letters.  After playing Sudoku for a significant period of time, I welcomed the extra challenge added by using letters instead of numbers. 

Wordoku To Go includes 200 puzzles divided into four different difficulty levels (warm up, easy, medium, and hard). This is a relatively small library of puzzles, and if you play Wordoku frequently, it will take little time to run out of available puzzles.  Nonetheless, it is encouraging that Puzzle Express is constantly working on new and improved puzzles, which are available from their website.  All of these updates are included free when you purchase the registered version of the game. 

Puzzle Express also recognizes, however, that playing a word based puzzle may take considerably longer than a traditional Sudoku puzzle.  As such, they have included a handy save feature which allows you to save any puzzle at any time during the game.  This means you can pick up exactly where you left off, a necessary feature for those of us who do not necessarily have hours at a time – or even 10 minutes at a time – to finish a game.

Finally, as I mentioned, playing Sudoku with words and letters instead of the traditional numbers offers a considerable challenge.  It can be difficult and frustrating to figure out the sequence of the letters, particularly in the harder difficulty levels.  For this reason, Wordoku offers a variety of options to nudge you in the right direction if you get stuck, all of which can be found under the Puzzle Menu.

• Check Square will check the answer you placed in the selected square and tell you whether it is correct.  Incorrect answers will be changed to italic font.
• Check All will check all of the answers you have completed up to that point in the game, marking the incorrect answers by changing the font to italics.
• Hint Square will add the correct answer in any selected square on the board.
• Hint Mystery Word will solve the mystery word in the shaded blocks across the middle of the board.
• Solve will complete the puzzle for you by inserting the correct answer in the blocks.
• Restart allows you to clear the board back to its original starting position and give the puzzle another try from the beginning.

There are also two buttons which reside under the gameboard at all times.  Space will clear the selected square, and Hint will correctly solve the selected square (this has the same effect as Hint Square).  I did find it odd, however, that you could select “Space” and clear one of the squares which had been completed as a clue to begin the game.  Accidentally clearing one of these clue squares can lead to considerable confusion, and even significantly alter the composition of the gameboard.  These clues should be fixed, and unable to be cleared during the middle of a game. 

One other notable omission was the absence of pencil marks.  Pencil marks are a critical tool for learning the strategies of any Sudoku based game, as well as solving the more difficult games.  The absence of pencil marks significantly hindered my ability to enjoy the higher difficulty games (I do recognize, however, that some Sudoku players would disagree with my reliance upon pencilmarks.  Nonetheless, this is an option which should be included for those who would choose to use them). 

The idea of using words and letters rather than numbers is a fantastic and original variation on the classic Sudoku format, and a fantastic way to start this roundup.  I do admit, however, that it took me a while to get used to the idea that this was not a crossword-sudoku type puzzle.  Our brains are trained to try to find patterns, such as words, in the chaos which is a set of nine seemingly random letters.  As such, I constantly found myself trying to form words in each row, column, and 3×3 grid.  Instead, only the gray shaded area in the middle is intended to spell a word. 

The graphics in this game are fairly minimal.  You can change the background color and text color to suit your mood, however, it would be fun to have a variety of images or skins in the background of each grid.  It would also be nice if you could change the font of the letters to add a bit more style to the game. Overall, however, I found that Wordoku To Go offered a new and exciting challenge to the growing genre of Sudoku variations.

Developer: Puzzle Express

Operating System: Windows Mobile 2003

Other Compatible Operating Systems: Windows Mobile 5, Pocket PC and Pocket PC 2002 (older Operating Systems require installation of the Microsoft .NET framework).

Test Device: Dell Axim x50v

Price: $10.00

Trial: Includes eight puzzles

Other Information: The full version also includes:

• complete Windows version
• Free updates including additional puzzles.

Where to purchase: Puzzle Express 

 

HEAD2HEAD SUDOKU

 

One of the downsides of Sudoku for me is the solitary aspect of the game.  There is not really an opportunity to directly compete against, or work with, other players.  Instead, Sudoku is a game which pits you against an unseen puzzle maker and, even more so, against yourself.  Now, thanks to Pyramid Peak Design, that has all changed.

Head2Head Sudoku is a truly original concept which allows 2-5 players to compete against one another, simultaneously attempting to solve the same puzzle over a network.  When one of your opponents has solved a square, that square will be colored red on your screen.  Additionally, if you want to work together, you can also put the game into cooperative mode, which allows you to see each other’s answers and solve the puzzle as a team. 

In order to play the cooperative or competitive games with other players, however, you must be connected to the same network.   This was unfortunate as it significantly limited my ability to enjoy an otherwise extremely innovative variation of this game.   This feature would be much more accessible if it allowed you to play with others via a Bluetooth connection, or seek out other players over the Internet.  Additionally, I was disappointed by the lack of an option to play a competitive game against the computer.

In addition to playing head to head with other players, you can also play a solo game.  I found that while the solo game in Head2Head Sudoku was adequate, it was clearly not the primary draw of the game and did not compare in terms of gameplay and graphics to other Sudoku games. The real attraction of this game, however, is the networking and competition option.

To its credit, however, Head2Head Sudoku does includes a virtually unlimited library of computer generated puzzles, as well as the ability to create your own puzzle.  Puzzles are divided into four categories: easy, medium, hard, and brain-buster.  You can also save any puzzle at any time, and reload it to start playing where you left off. 

Another feature which I truly enjoyed and appreciated, even in the solo game, was the presence of the timer.  This is a fantastic way to determine how you are progressing in your Sudoku ability.  Your previous puzzle time and average times are stored in the statistics, so you can always check back and see whether you are improving (or not…). 

One of the more common methods of solving Sudoku puzzles involves the use of pencil marks, or small digits placed in the corners of the boxes.  These are used to indicate the potential answers for a particular box in the grid.  Much to my disappointment, however, Head2Head Sudoku does not allow for pencilmarks.  Instead, you can set it to place a mark in one or more of nine positions in each box, to indicate each of the available solutions for that box.  I did not like the candidates option, although I am aware that this is a popular method for solving Sudoku puzzles. 

I found that Head2Head Sudoku was a fantastic game, if you have the ability to connect with other players via a network and play the competitive or cooperative games.  Without this feature, however, the solo game simply did not stand out from the dozens of other Sudoku games available for Windows Mobile devices. 

Developer: Pyramid Peak Design

Operating System: Windows Mobile 2003

Other Compatible Operating Systems: Windows Mobile 5, Windows CE 4.2 or greater

Test Device: Dell Axim x50v

Price: $7.95

Trial: 30 days

Other Information: The multiplayer game requires a TCP/IP network connection, such as WiFi.

Where to purchase: Pyramid Peak Design

 

KOKONOTSU

There is a common misconception that Kokonotsu is just a more difficult version of Sudoku.  To be sure, this idea is supported by the fact that gameplay in Kokonotsu (which is also known as Super Sudoku) is only one small twist away from traditional Sudoku.  As such, it has become the game many Sudoku players turn to for a slight extra challenge before they graduate to the more difficult variations.  The origins of the game, according to the official Kokonotsu website, are vastly different, however, than Sudoku.

Although they may look similar Kokonotsu and sudoku are not related in any direct way other than that both are puzzles.  Their relationship can be compared to the relationship between a calf and a foal: Both are four-footed animals and at first glance appear to be alike, but that is where the similarity ends. They have totally different blood and digestive systems, totally different sight sensors and one has a divided hoof while the other hasn’t.

And while sudoku is a relatively new puzzle Kokonotsu’s origin can be traced back more than 6,000 years to the Chinese Magic Square symbolizing perfect harmony and connectivity. With this simple nine-field square the ancient Chinese were able to explain the function of our Universe and everything in it.  The Chinese Magic square is the underlying principle, heart and foundation stone of feng shui and traditional Chinese medicine. It represents ourselves and the heart that encompasses the full range of experience, from our inner self to our interaction with the world at large.  The ancient Chinese Magic Square was followed by the Lo Shu Square, which dates back to 2200 B.C. It symbolizes the natural order of the Universe, promoting logic, strategy and open-mindedness. Reference to it can be found in a book entitled “Yih King.”

The Legend of Lo Shu

During ancient times in China there was a huge flood on the Lo River. The people tried to calm the river god’s anger by offering sacrifices, but each time they prepared an offering a turtle came up from the river and walked around the sacrifice, and the river god wouldn’t accept the sacrifice. This happened several times, until one time, a child noticed curious markings forming a pattern on the turtle’s shell. After studying these markings the people realized the correct amount of sacrifices to make – 15 – and then the river god was placated. The numbers in every row, up and down, across, or diagonally, add up to 15, which happens to be the number of days it takes for the new moon to become a full moon.

From that ancient magic square philosophy, came the Kokonotsu Magic Cube and the Kokonotsu Puzzle. Unlike sudoku, these are based on true magic squares and, although ancient in origin, they provide perfect mental exercise for those of us living in a modern technological world. They’re very engaging, providing the brain with a brisk workout calling for logic, strategy and reasoning.  As a bonus, they are great stress-relievers. 

Kokonotsu adds a fourth and fifth dimension to the traditional Sudoku puzzle, by requiring that the two main diagonals which cross the center of the puzzle to also contain the numbers 1-9 without repeating.  Additionally, every Kokonotsu puzzle contains a "magic heart".  Solving the magic heart will help extremely talented players solve Kokonotsu puzzles even faster.

Mud Inc.’s Kokonotsu puzzle for Windows Mobile devices is an extremely well made version of the game, which employs both traditional elements, as well as modern graphics to immerse you in the game.  Beginners can learn the game and its strategies by playing on a 4×4 grid instead of 9×9.  More advanced users, however, may wish to increase the difficulty of the game by playing Kokonotsu using colored dots or various shaped icons instead of numbers. 

Much to my disappointment, Kokonotsu does not allow for pencilmarks.  Instead, you can set it to place a small dot in one or more of nine positions in each box, to indicate each of the available solutions for that box.  Although I do not typically use this method to solve Sudoku puzzles, I did like, the fact that Kokonotsu adds the ability to magnify each box for a closer look at the marks.  Simply click on the box and tap the marks button to view a larger image of the marks in that box.  Tap on any of the marks to eliminate them from consideration as a possibility.

Additionally, the game will automatically alert you if your proposed solution creates a conflict.  In that case, the row, column, grid, or diagonal in which the conflict exists will flash and you will be unable to place that answer.  While this was a nice feature for those learning to play, I would have liked the option of stopping this feature once I became more proficient at the game.  Additionally, as with other Sudoku variations, you can always ask for a hint at any time, or simply instruct the game to solve the entire puzzle. 

Kokonotsu also includes two alternate modes which help increase its functionality.  The Edit Mode allows you to create your own puzzle to solve.  Unfortunately, I noted that this mode does not turn off during gameplay, meaning you can edit the puzzle on which you are currently working.  This, obviously, lends itself to cheating by allowing you to edit the puzzle to fit the guesses you have already made.  Additionally, you can also select to play in traditional Sudoku mode instead of Kokonotsu, while still maintaining the exceptional graphics of this game.

 Kokonotsu was the first Sudoku variation I played after I became proficient at the game.  Although it may not have been born from Sudoku, it is a great first step away from the traditional game because gameplay is extremely similar.  Mud Inc. did a fantastic job with this game, creating extremely well drawn graphics, and five different difficulty levels.  This is a great game for any Sudoku player who is ready to take the next step into the wider world of Sudoku variations.

Developer: Multi User Design (Mud), Inc.

Operating System: Windows Mobile 2003

Other Compatible Operating Systems: Windows Mobile 5, 

Test Device: Dell Axim x50v

Price: $14.95

Trial: Unlimited 4×4 gameplay.  9×9 grid in beginner mode only

Other Information: Be sure to also check out the official Kokonotsu web page for additional information.

Requires 16 bit color and a 176×220 device.

Where to purchase: Multi User Design, Inc.

 

SUDOKU GL

Sudoku GL offers another unique and original interpretation of the traditional Sudoku game.  The object of the game has not changed, nor has gameplay.  What has changed, however, are the clues you are given.  While you will still receive a small field of numbers which have been completed for you to set the board; your main clues will come in the form of greater than (>) and less than (<) signs — hence the name Sudoku GL.  By using these signs, which lie between the boxes, you can determine the sequence of the numbers and complete the puzzle.  This twist – which requires you to pay attention to the relationships between the numbers, not just their positions on the board — adds a significant new challenge to the game, which I thoroughly enjoyed.  Then again, I was told there would be no math in Sudoku, and this certainly does require some elementary math to take place. 

Sudoku GL offers thousands of puzzles, divided into five levels of difficulty (easy, regular, medium, hard, and extreme).  In addition to selecting the difficulty level, you can use the options menu to fully customize the look and feel of the game.  You can control what information is displayed and how it is displayed.  You can also determine the look and feel of the gameboard and colors, as well as which strategy hints can be displayed.  Furthermore, if you get stuck or simply need to take a break, you can save your game at any time and reload it when you are ready to continue.

During gameplay, you can also request a great deal of information.  Select a number and you can highlight each occurrence of that number.  If you have symmetry turned on, then this can give you quite a significant amount of information about the puzzle, and help you deduce the remaining locations of that number.  You can also highlight a 3×3 square, or seek hints by shapes on the board (there are a variety of Sudoku strategies based upon these shapes).  These options are excellent learning tools.  For example, the game can be set to highlight (or even block) incorrect answers, which helps learn the basic rules and strategies.  Once you become familiar with how to play, you can turn these features off and play a considerably more challenging game. There are also two additional game modes offered with Sudoku GL, Sudoku Scramble, in which you must race against the clock to solve the puzzle; and Sudoku Blackout.

Between the two optional game modes, and the vast amount of information available through hints on the screen and various available strategies, I could not help noticing the lack of any instructions (either in the game or on the website).  Because so much information can be used and conveyed, an instruction manual or help guide would seem to have been necessary.  I did search Spiral Mile’s website and found much, but not all, of the information I was seeking in the manual for one of their other games,Sudoku Rules Extreme.  Nonetheless, I still cannot understand what to do in Sudoku Blackout mode, and I had a difficult time deciphering much of the information on the screen. As such, I hope a manual with further instructions will be forthcoming.

Despite this lack of documentation, Sudoku GL was extremely playable.  I loved the extra challenge it provided, as well as the extreme level of customization.  Additionally, if you can decipher the hints and strategies displayed on the screen, then this can also be among the best Sudoku variations for beginners who want to learn more about the advanced strategies.  In the end, I felt the gameplay and advanced features made this game GREATER THAN many Sudoku games; however, my experience with it was LESS THAN it could have been because much of the information on the screen was simply not explained.

Developer: Spiral Mile

Operating System: Windows Mobile 2003SE

Other Compatible Operating Systems: Windows Mobile 5, Pocket PC 2002, Windows Mobile 2003, Window Mobile 6, Smartphone, Windows 98 (desktop) and higher.

Test Device: Dell Axim x50v

Price: $12

Trial: Unlimited gameplay in easy mode.

Where to purchase: Spiral Mile

 

THE SUDOKU COLLECTION

One of the most common variations of traditional Sudoku is changing the dimensions of the gameboard.  By making it smaller (4×4) you make a significantly easier game for beginners.  By making it larger (16×16) the degree of difficulty expands significantly.  These are the options presented by Pocket Adventure’s Sudoku Collection.

When you begin the game, The Sudoku Collection gives you the option of selecting from any of the three grid sizes (4×4, traditional 9×9, and 16×16).  Of course, most Sudoku is played on a standard 9×9 grid.  If you are just learning the game, or want to test out a new strategy, however, try the 4×4 grid.  Its small size makes it an ideal training ground.  On the other hand, if you are an advanced player, looking for a Sudoku marathon, then you will want to select the 16×16 grid.  Within each grid size, you can also select from three difficulty levels (easy, medium, and hard).  With nine different levels of difficulty, The Sudoku Collection clearly provides a game which is appropriate for players of all levels from the beginner to the most advanced professional (if there is such a thing).

Once your puzzle has loaded, you will notice the extraordinarily well drawn  skin of the puzzle.  It is rare to see such attention to the graphics in a puzzle game.  The Sudoku Collection affords you eight VGA skins, each of which displays a unique wallpaper behind the puzzle and themed font.  The Sudoku Collection will even provide you with a fantastic fireworks display when you successfully complete a game.  Frankly, there is nothing I appreciate more than a mini-celebration with myself after I have completed a difficult puzzle.  More games should offer a similar option.

In addition to the skins, The Sudoku Collection also offers sound effects as well as three different background songs.  I really appreciated these extra touches that were put into the game.

From the Menu button, you can also save a game, load a game, or create your own game board with the Edit Button.  Additionally, each game you play will be added to your statistics so you can track your progress through each of the various levels.

For the beginner, there are two options which are designed to help you learn the rules of Sudoku quickly.  First, you can turn on the Auto-Pencil Marks Option.  When this option is activated, tapping the Pencil button will add pencil marks showing each available option in every blank square on the grid.  With the Auto-Pencil Marks option turned off, tapping the pencil button will allow you to toggle between solving the square and manually adding pencil mark suggestions in each square. 

Additionally, you can choose to Limit Numbers.  With this option checked, you will not be able to place a number in any square if it would create a conflict.  If you get really stuck, you can also just tap the hint button and the game will reveal the correct solution for the selected square.

Finally, each time you begin a game, a new puzzle is randomly generated.  This means you can have unlimited gameplay of each of the three board sizes.  If this is not enough for you, however, Pocket Adventures offers a Puzzle of the Day which can be downloaded directly to your device by any registered user of the game.

The Sudoku Collection offers one of the nicest looking Sudoku games I have played.  With nine levels of difficulty, this is an ideal version for any player, regardless of skill level.  Finally, the attention to detail in the the skins, graphics, and audio provides the icing to this deliciously addictive game.   

Developer: Pocket Adventures

Operating System: Windows Mobile 2003SE

Other Compatible Operating Systems: Windows Mobile 5, Pocket PC 2002, Windows Mobile 2003,

Test Device: Dell Axim x50v

Price: $9.95

Trial: Gameplay is easy mode only with some options disabled.

Other information: Support for QVGA, VGA, and Square Screens

Where to purchase: Pocket Adventures

 

SUDOKU SOLITAIRE

Sudoku Solitaire from Stylus Games is probably the most original Sudoku variation I found.  While it follows the rules of Sudoku in a general sense, it turns them upside down by adding elements of the card game Solitaire.  What results can be an extremely fun and addictively frustrating game, which will really tax all of your Sudoku and Solitaire strategies.

The game consists of ten different games or levels, which are ordered according to difficulty.  As such, while you can play any of them at any time, I suggest starting at the top of the list and working your way down.  In fact, I would have preferred that some of the more difficult levels remain locked under earlier levels were completed.  This would ensure that you gradually ease yourself into the more difficult and complex games, and learn about the behavior and strategies of the game before attempting the more difficult levels. 

In each game, you are faced with a 6×6 grid which is divided into six irregularly shaped sections.  Instead of using numbers, you will find pucks scattered about the board.  Each puck contains a picture.  Like Sudoku, your job will ultimately be to arrange the pucks in such a way that no row, column, or irregular section, contains more than one of each puck. 

At the bottom of the screen, you have a shooter which contains all of the additional pucks available to you.  By firing these pucks onto the game board, you can unlock additional pucks which will help you solve the game.  This is the Sudoku part of Sudoku Solitaire.

Once you have mastered the first three levels, it is time to add the Solitaire portion.  In the remaining games, instead of pictures, the pucks will contain playing card values.  In order to solve the game, you will need to fire the pucks onto the board in such a way as to create a chain of card pucks (for example, 10,J,Q).  Each of the seven card-based games in Sudoku Solitaire has slightly different rules, which keeps the game fresh.

With this groundwork in mind, the ten games (or levels) included in Solitaire Sudoku are:

• Childs Play : A six by six Sudoku game with pucks and unlocking.
• Salute the Flag: A color Sudoku puzzle.
• Bomb Disposal: A color Sudoku where bombs explode if you put the wrong symbol on a bomb square. Or if you uncover two matching symbols in the shooter.
• On Return to my Newspaper. A Suduko of swapping tiles. But you must keep to Sudoku rules at all times.
• Cabin Fever: A Sudoku cross solitaire. Solve the Sudoku then place the cards with solitaire rules and find the unlocks.
• Gone Fishing: Another variation on Sudoku Solitaire.
• Old sKool: Sudoku Solitaire as close as I could make the rules. Even the turn over of three cards is re-created.
• Whistling Forest: Sudoku Solitaire with less pucks to unlock and a no pencil marks a true test of memory.
• 2 Modified Games: You can make up your own rules. Infinite boards and infinite rules the fun is infinite.

Every time you start a new game, a fresh arrangement of tiles is randomly generated, meaning there is a virtually unlimited number of puzzles from which you can select.  Each puzzle also offers a variety of skill levels so that you can start off playing an easier game and graduate to a more difficult one without changing the rules or switching to a different variation.

If you get stuck on a particular game, you can also select Tiny Little Cheats from the Menu.  This will give you a variety of hints from which you can select in order to help you complete the game.  For example, if you select Pencil Solution, then the game will add pencil marks to each unsolved square. 

Sudoku Solitaire is an extremely complex and original game.  As such, you would expect a relatively in depth manual, explaining the rules of each game variation, and the allowable movements and controls.  Instead, however, I found only a short paragraph overview of each game.  Because this game is so unique, I found the lack of any available instruction to be extremely frustrating.  Although this is an incredibly original and well conceived game, it was too frustrating for me to try to learn without more comprehensive instructions.

Developer: Stylus Games

Operating System: Windows Mobile 2003SE

Other Compatible Operating Systems: Windows Mobile 5, 

Test Device: Dell Axim x50v

Price: $5.95

Trial: None.  However, a free version of Bomb Disposal is available.

Other Information:  This game costs $5.99, however, for $4.99, you can purchase the Stylus Games Golden Pass which will provide you with unlimited access to Sudoku Solitaire, Atlantis Games, and Stylus Games’ next two releases.

Where to purchase: Handango

                                 Stylus Games Forum

 

KILLER SUDOKU

Killer Sudoku introduces math to the basic Sudoku equation.  So, if the big draw to Sudoku for you was that it is a numbers based game which uses no math…well, Killer Sudoku may not be for you.  For the rest of us, however, it is an extremely challenging variation on the traditional game, as well as a bridge to another fantastic Japanese numbers game, Kakuro (but that is another article).

In Killer Sudoku, you are still faced with a 9×9 grid.  In addition to being subdivided into smaller 3×3 grids, however, the 81 boxes in the grid are also divided into irregular groups.  Each group will be outlined or shaded and contain a small number in the corner.  This number is the total value of that group.  When solving the Sudoku puzzle, the numbers in each group must add up to that group’s total (while also following the basic rules of Sudoku). 

ISS Killer Sudoku features five difficulty levels ranging from Very Easy to Very Hard.  The more difficult levels will have larger and more irregularly shaped groups, while the easier levels’ groups will be arranged in a small, straight patterns.

There are also three different skins, each of which was extremely well drawn. 

• Cool Skin has a nice, crisp feel to it.  It features a  white background  with a black grid and text.  Each group of numbers is outlined in blue.
• Hot Skin is the best skin for novice Killer Sudoku players.  It shades each group of boxes a different color, making it extremely easy to identify which boxes have been grouped together.
• Newspaper Skin attempts to simulate the look and feel of a newspaper puzzle.  The groups are outlined in a dotted line, which can make them extremely difficult to see.  The group on which you are currently working, however, will be slightly shaded.

Gameplay of Killer Sudoku proceeds in a manner which is identical to traditional Sudoku.  Simply tap on any box, and the number entry dialogue will pop up.  From there, you can select whether you want to enter a number or a pencil mark, and then tap the number you wish to use.  Across the bottom of this dialogue, are two rows of numbers which show you the remaining possibilities for that box, as well as the total value of the group. By showing you the potential remaining answers, however, the game has done much of the work for you, particularly in Killer Sudoku which is based so much on math.  The possibility of placing a wrong answer based upon a mathematical mistake is virtually eliminated.  Therefore, while this feature was nice for learning the rules of the game, once you have become adept at it, you will find that it limits the difficulty of the game significantly.

Of course, like virtually all of the Sudoku variations, you can save your game.  Each time you exit the game, your progress will be automatically saved, overwriting any previously saved games in the process.

There is not an option to receive any in-game hints or tips, however, if you get really stuck you can always tap solve and have the game solve the entire puzzle for you.  This is a helpful tool, which you can use to determine what mistakes you made and what you could have done differently to solve the puzzle.  With an unlimited supply of puzzles, however, it is unlikely you will see that one again.

Implicit Software has done a fantastic job with this game.  I found the skins provided an ideal environment for learning the game (Hot Skin) as well as a pleasant atmosphere for more advanced players (Cool and Newspaper Skins).  Although there were no in-game hints, the game will tell you which options are available for each block.  Killer Sudoku is one of the more challenging variations of Sudoku, and this challenge was well represented by Implicit Software.

Developer: Implicit Software Solutions

Operating System: Windows Mobile 2003SE

Other Compatible Operating Systems: Windows Mobile 5, Smartphone, Blackberry, Soleus phones

Test Device: Dell Axim x50v

Price: $14.95

Trial: There is a limited trial available.

Other Information:  ISS Killer Sudoku is part of the ISS Sudoku package.

ISS Killer Sudoku is also included in the ISS Gamepack 2, which costs $24.95.  In addition to Killer Sudoku and Sudoku, GamePack 2 also includes: Minesweeper, Poker Solitaire, Polyminoes, and Trixec.

Where to purchase: Implicit Software Solutions (ISS)

 

SUDOKU 3D

Sudoku 3D, or Sudoku Cube as it is often called, is probably the most ambitious Sudoku challenge I have ever encountered.  The first time I attempted this variation, it was actually published as part of a Sudoku contest.  I worked on it for days, and finally arrived at a solution which I am fairly confident was correct.

The basic variation here, as the name would imply, is that the board exists in three dimensions instead of two.  In this version, the basic grid is 4×4, which means that it is a 4×4x4 cube (4 grids, which are each 4×4, stacked on top of each other.  In addition to solving each two dimensional grid, the grids must also fit together in three dimensional space, so that every 2×2 square and each row in all three directions (horizontal, vertical, and depth) contains the numbers 1-4, without repeats.  This means you must be constantly aware of how the grids relate to each other in order to solve the puzzle.

In order to facilitate solving the puzzle, you can view it in two different modes.  In the default 2D mode, all four grids are spread out on the screen, flat, so that you can view them all together.  You can only enter numbers onto the grid in 2D mode, which I found to be unnecessarily limiting.  Oftentimes, I would identify a relationship in 3D mode, only to be forced to track my answer back to 2D mode; all the while, monitoring the box in which I believed it should fit.  This simply left to much room for error, and there should be a way to enter numbers in 3D mode as well.

Tap switch to 3D and your grid transforms into a series of numbered balls  (arranged in the same pattern as your grid.  From here, tap the 3D button and these balls will form themselves into the Sudoku cube.  One of the truly amazing features in this mode is the animation.  You can rotate the cube in any direction, simply by dragging it with your stylus.  Additionally, you can separate the cube back into four grids along any of the three axis.  To return to the 2D grids, simply separate the cube along one of the three axes and tap 2D.

If you get stuck at any time, you can ask for a hint, which will complete the correct answer in the selected box.  You can also check your answers.  This will tell you if whether any of your answers are incorrect, without identifying which answers you have right or wrong.  I liked this system, because it forces you to keep analyzing the puzzle, rather than simply spoon feeding you the correct answer. Additionally, you can ask the computer to show possible values for any particular box, without solving it.  This will black out any numbers which cannot be the correct answer.  Or, you can simply solve the puzzle.

This brings me to the unique means by which this game handles pencilmarks.  At the bottom of the screen is a panel with the numbers 1-4.  These numbers are used to input your guesses into each box.  Simply select the box and tap the number you want to add there.  If you are unsure of an answer, however, tap the bottom half of the number button and that number will be blacked out, meaning that it cannot be the correct answer for that box. This will help you use the process of elimination in order to deduce a correct answer, however, it does make it more difficult to examine the relationships between potential answers in various boxes.

I was disappointed to find that the game only includes 320 potential puzzles.  For a Sudoku game, this is frustratingly low.  One nice option, however, is that you can save your progress on any (or all of them) and continue it at a later time.  Additionally, there is only one level of difficulty.  While the game is plenty difficult as a 4×4x4 cube, true traditionalists will seek out the challenge of playing a 9×9x9 Sudoku cube.  It would be nice to have the option of playing at that level.

Sudoku 3D literally takes Sudoku to a whole new dimension.   By converting a traditionally two dimensional puzzle into a three dimensional cube, the difficulty level increases exponentially as there are significantly more factors and relationships to maintain.  Try it for yourself.  Play a traditional 4×4 Sudoku and then play the 4×4x4 cube Sudoku here and you will see the vast difference in challenge.  Nonetheless, I would have liked the option of playing the ultimate Sudoku challenge here, the 9×9x9 Sudoku cube.  Even without this option, however, Sudoku 3D offers an extremely challenging and well made Sudoku variation.

Developer: Colemanik

Operating System: Windows Mobile 2003SE

Other Compatible Operating Systems: Windows Mobile 5. 

Test Device: Dell Axim x50v

Price: $4.99

Trial: A limited trial is available as a separate download file.

Where to purchase: Pocket Gear

 

 MULTISUDOKU II

I saved MultiSudoku for last on purpose.  Now that you have learned about a number of different Sudoku variations, it is time for you to start building your own puzzles.  This is a great Sudoku resource which is more  Sudoku generator than a Sudoku game.  By generating your own puzzles, however, you can learn a considerable amount of information about the advanced strategies necessary to solve traditional Sudoku puzzles, as well as many of the variants. 

When you start a new game, you will be faced with a blank Sudoku grid (a standard 9×9 puzzle).  From here, use the number bars on top to generate a standard Sudoku puzzle by placing the numbers 1-9 throughout the grid. Pay attention to how difficult you want the puzzle to be when placing these numbers.  You can enter a puzzle you found in the newspaper, a book, or even just create one from scratch.  You will want to be sure that you have entered a valid puzzle, with only one unique solution.  To do so, tap the blue flag to validate the puzzle. 

Multi Sudoku, however, is much more than just a traditional Sudoku editor.  Under the File Menu, tap new to open the Sudoku generating menu.  From here, you can control exactly the look and feel of your board.  Change the size from as small as a 4×4 small board (listed as 2×2) to as large as a 16×16 enormous board (listed as 4×4).  You can also change the difficulty level to make the puzzle as hard or as easy as you wish.    Click on the distribution option to change how the clue numbers are distributed on the screen.  You can select anything from all around the center, to leaving one side empty, and more.  Additionally, you can always enter the numbers manually, by selecting the “Empty” button to generate a blank grid.

Another variation of the traditional Sudoku puzzle, which is supported by Multi Sudoku is Puzzle Sudoku or Jigsaw Sudoku.  In this variation, which can be accessed by selecting the Puzzle option, the blocks are divided into irregular shapes, each containing 9 blocks.  To solve a puzzle, you must include all of the numbers from 1-9 in each irregular shape (as well as following the additional rules of Sudoku).  Puzzle Sudoku is a fun variant of the classic game, and I was glad to see it supported here.  Additionally, Multi Sudoku can incorporate the rules of Super Sudoku (Kokonotsu) by including one or both diagonals in a puzzle.  If a diagonal is selected, then you must include all of the numbers from 1-9 on that diagonal.

This means, you can generate a total of five different games, plus various combinations of them (for a real challenge, try combining Super and Puzzle Sudokus on a 16×16 board, as seen on the left ). 

I know a lot of people who prefer a colored Sudoku board rather than a plain one.  You can generate up to 16 different colors onto the board, in a random pattern, block pattern, or puzzle pattern.  Additionally, you can even use pencilmarks and hints to help you solve the puzzles after you have generated them.

Once you have created your new game, you can find it again by selecting the Generated option.  This will allow you to open any of the grids that you have created thus far.  Be sure to hit save on any you want to keep before you exit, however, or your generated games will be erased.  Furthermore, if you want to make changes to the layout once you have completed generating a new game, just tap edit to fix it.

Multi Sudoku is a fantastic option for beginners and advanced players alike.  By allowing you to generate puzzles in several different Sudoku variations, it will help teach some of the more advanced strategies, while also providing a great Sudoku resource.  In addition to automatically generating puzzles, it allows you to manually input puzzles from the newspaper or other sources, which means you will never have to worry about newsprint or eraser mess again.  Finally, there is nothing quite like starting with a blank Sudoku screen, ready to create a new challenge for your friends.

Developer: Wursag

Operating System: Windows Mobile 2003SE

Other Compatible Operating Systems: Windows Mobile 5, Windows XP

Test Device: Dell Axim x50v

Price: $12.95

Trial: A limited trial is available as a separate download file.

          Requires the .net CF 2.0 framework.

Where to purchase: Multi Sudoku Homepage

As you can clearly see from this article, I am totally addicted to the game of Sudoku.  In fact, it was love at first sight for me after playing it one time in the Washington Post.  Since then, I have even competed in a local tournament (I placed in the top 20 out of thousands of entrants).  Sudoku, however, is just the mere tip of the iceberg when it comes to the world of Japanese puzzle games.  I have found that many of them are based upon similar concepts, so once you become adept at Sudoku, the strategies and techniques will carry over into games like Kakuro, Japanese Crossword, Hitori, and more.  As such, I am planning a follow-up to this article, based upon all of different Japanese puzzle games available for the Pocket PC. 

Additionally, you may have noticed that your favorite Sudoku variation was left out of this roundup.  I was saddened to find that there are numerous variations, such as Samurai Sudoku and the daunting 25×25 Sudoku grid, which are not available on the Pocket PC.  As new variations are released in the future, I will continue to update this roundup, or publish a second edition.  In the meantime, if you know of (or developed) a unique variation which was not included in this roundup, please email me at doug at justanothermobilemonday.com, replacing the "at" with a "@".    

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