Gadgetorama reviews Mastersoft SuDoku by Mastersoft Mobile Solutions

By Jerome, Editor-in-chief
Posted on September 21, 2005


A SuDoku craze has been sweeping the world: Newspapers have added them to their games sections, radio shows have devoted entire segments to the phenomenon, web sites where you can play online are everywhere and it seems that a different company releases a version for the computer or Pocket PC every other week. You simply cannot escape it!

If you play one of the newspaper versions, you will probably agree that this is one medium that does not lend itself well to the deduction and guesswork that come with the game. With a moderately challenging puzzle, you might find yourself running out of room in each square for your guesses or erasing so much that you'll simply be left with a hole in the paper. Fortunately, Mastersoft Mobile Solutions has developed a version for the Pocket PC that will allow you to let go of the eraser and take your puzzles everywhere.

A little history

SuDoku dates back to the 1970s and originated in the United States. In 1984, a Japanese company started publishing the puzzles under the name Suuji Wa Dokushin Ni Kagiru, a name that means that numbers can only occur once. In 1986, the game underwent some changes and the name was shortened to SuDoku (Su = number, Doku = single or unmarried). In 2004, the game started to catch on outside of Japan with newspapers like The London Times, The New York Post, The Daily News and USA Today launching daily puzzles. It seems to be everywhere now.

Beginning a new game
Figure 1: Starting a new game
Game in progress
Figure 2: Game in progress


Mastersoft SuDoku requires about 7MB of storage space and the Microsoft .NET Compact Framework (standard on all Pocket PC 2003 and higher devices). If you need to install it, you can download it from Microsoft.

Installing SuDoku is very easy. You simply run the executable file and follow the prompts. I am running the game from my SD card with absolutely no issues. Once the installation completes, you will get a warning that the program may not display properly on a WM2003SE device (this is due to landscape mode in SE).

Upgrading to new versions was just as easy. I simply installed over the existing version and never ran into any issues.

Time to solve some puzzles

Time to go solve some puzzles! After a quick splash page, you will find yourself at the main screen. As you would expect, most of the screen is devoted to the puzzle that you are working on - a 9 by 9 grid subdivided into 3 by 3 subgrids (Figure 1). Under it, you have a game timer, a Ying and Yang symbol, the current game score and a coloured shield (representing your rating). Below that you have the menu bar with options like the eraser that will take back your last move.

Mastersoft SuDoku comes with 6 different difficulty levels. The harder the level, the fewer starting numbers you get. Deduction will not get you as far and you will need to depend on guesswork a lot more. Creating a new puzzle does take a few seconds (up to 20 seconds or so for more complex puzzles). During this process, the generator will ensure that there is only one solution and set up the hints that you may use as you play.

The timer keeps track of how long you have been working on the puzzle. You can pause the timer at any time but a screensaver kicks in. No peeking while the timer is paused. You also start each game with a certain number of points (more for higher difficulty levels) and these steadily dwindle as time elapses.

While most SuDoku games do not offer this scoring feature, it is something that you can use to compare your puzzle solving skills against others (or yourself) if you have a bit of a competitive streak. You can turn it off (as well as the timer) if you want to avoid the added pressure of points and timed games. I did run into an issue where my score feature would suddenly drop to zero after a game pause. It only happened twice (and not since I upgraded to v1.1x) but it was a real nuisance, especially when a high score was just around the corner.

Version 1.1 introduced a lot of new features that nicely complement the game. The first two (and very cool) features are called the Ball of String and Flag Trails. The first is simply a history of all your moves. At any time, you can go back to any move that you made in the past. To identify milestones, you can use a flag. When looking at the Ball of String, moves that you flagged will show up with the appropriately coloured flag. For example, in Figure 3, the Ball of String shows the moves I have made so far with 2 moves marked with green flags. One warning: Once you have gone back to an earlier move, the subsequent moves are lost so you cannot then jump forward. And a word of warning: the Ball of String information is lost when you close (but not when you minimize) the game. This helps preserve system resources.

Ball of string
Figure 3: Ball of String

A cumulative score of all your games and summary of number of SuDoku puzzles solved is maintained (and can be seen by clicking on the Ying and Yang symbol). But when I upgraded from version 1.0 to 1.1, the cumulative score was maintained but other statistics were lost. It looked odd that I had this cumulative score but no individual scores! Since version 1.1, more detailed statistics are also available: For each difficulty level, you can now see information like best, average and worst times.

Sometimes, a change of perspective can be useful and this is where the Grid Transform feature comes in. It lets you rotate the puzzle in different ways to give you a different view of it. Again, a very cool feature that does help when you think that you're about to go cross-eyed. And if that's not enough, the transform is fully animated - it does nothing for the game but it is neat to watch.

When you get stuck, Mastersoft SuDoku comes to your rescue with 14 different types of hints. For example, with Possible Values for a Cell, you can see which are valid for that cell. Use Highlight Singles to see all cells for which only one value is possible. But hints come with a very high price. Games where you used hints will be excluded from statistics and your game score will immediately drop to 0.


At the heart of this game is the input method that allows you to quickly enter your answers. With the necessity to keep track of guesses, sure bets and different cell permutations, a way to easily input this information is key. When you click on a cell that does not have a fixed number (ie, one provided by the puzzle), the keypad will come up. This keypad controls all of your inputs. Two input types are possible: Standard (Figure 4 on the left) and Memo (Figure 4 on the right). The former is used for numbers that you are (relatively) confident about. The second is like a scratch pad where you put down your guesses or possibilities. With memo mode, you can enter up to all nine numbers in a cell. For such a small font, I was impressed by the legibility of the digits.

Keypad views
Figure 4: Keypad views
Pen colours in use
Figure 5: Pen colours in use
Picture Puzzle
Figure 6: Picture Puzzle

In Standard mode, you also have the ability to colour-code your numbers. This is really useful. For example, I can use one colour for the numbers that I absolutely know are correct. If I get to a point where I have to take a guess to move on, I can switch colours to identify the numbers I entered after my guess (I used this approach a lot before the new Ball of String feature was added to the game).

Version 1.1 of the game has tweaked the keypad with some new features that greatly improve gameplay. For example, I activated 'Sticky pad' so that the keypad did not disappear as I switched between different cells. I found this feature really useful when working in Memo mode where two or three cells in a subgrid that all have a possible value. You can also enable keypad dragging (using the stylus) with 2 different levels of sensitivity.

Overall, Mastersoft has done an impressive job with the keypad. It offers one easy-to-use interface that allows you to not only put down the numbers you are fairly confident about but also your outright guesses and cell possiblities.

Graphics, Sounds and Music

Given that this is a puzzle game, the requirement for high-end graphics is low. Instead, we get a game with a clean and elegant layout. The different skins are all well designed and easy on the eyes. As I indicated earlier, I was impressed by the legibility of the very small number font in memo mode. It does show that careful attention was paid to the graphics.

For those who like even more challenge, Mastersoft SuDoku offers skins that do not use numbers but images (Figure 6 shows the Harmony skin). The image sudokus are even harder to play and are recommended only for brave souls.

One area where Mastersoft SuDoku stumbles is support for landscape mode. As you can see in Figure 7, to play in landscape mode will require that you scroll up and down because the puzzle cannot be seen in its entirety. Let's hope that a future version addresses this.

Furthermore, Mastersoft SuDoku does not have a version for VGA mode. The QVGA version will run on VGA devices but will do so more slowly. On the other hand, a special version for the iPAQ hw6500 with its square screen is available.

Landscape mode
Figure 7: Landscape mode

The game comes with only 6 sound effects. Given that this is a puzzle game, I think that this is a good thing: Excessive sounds would only distract the player. And if even these six sound effects are too much for you, you can either turn off individual sounds (like Transform and Hint Found) or turn them all off.

Other features

Aside from the millions of SuDoku puzzles that the game can generate, you can enter your own SuDoku puzzles and solve them. I like the fact that the hint tools will work even on these imported puzzles. And if you decide to enter a puzzle that cannot be solved, Mastersoft SuDoku will stop trying after 30 seconds, preventing a device lockup. For fun, I entered a couple of puzzles that appear in one of the local newspapers. Neither of them posed any difficulty to the puzzle solver.

Mastersoft SuDoku also allows you to import and export puzzles. Two formats are offered: SuDoku file and simple text file formats. The former will allow you to export your game as well as settings such as the notes made in memo mode. The latter will simply export the game grid and numbers. I don't think that this function will get much use but it does allow you to easily export a puzzle and send it to someone else for example.

What I liked

  • Ball and thread system
  • Over one million puzzles to solve
  • Keypad input is flexible and intuitive

What I did not like

  • No VGA mode but it is coming
  • Poor landscape mode support
  • Small bugs (none affecting game play)


While there is now a plethora of SuDoku games for the Pocket PC, I can't think of any that comes with as many functions to help you play the game as Mastersoft SuDoku. Mastersoft spent a great deal of time working with beta testers, trying different things and ultimately ended up with a game that not only is easy to play but also comes with a gamut of supporting functions like different types of hints, the Ball of String feature, a grid transform function and more. What most impressed me though is the keypad and its customizability. You will find that it makes it really easy to enter not only your answers but also all the cell permutations that you have not ruled out yet.

In the end, if you like puzzle games, I think that you will like SuDoku (if you haven't already tried it) and Mastersoft SuDoku will make the puzzle solving even more enjoyable.


45 out of 5

Where can I get it?

You can purchase SuDoku from Mastersoft for $14.95 USD. A version for the iPAQ hw6500 (240x240 screen) is also available.

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