Rainer Herrler






4.5 Star Rating: Very Good

Rainer Herrler Mobile-Sudoku 2.0 for Handheld PC

John Ottini | Handheld PC Reviews
July 17, 2006

It’s fairly difficult to read a newspaper, stop by a newsstand or run through the checkout line at your local supermarket, without noticing those curious little Sudoku Puzzles, which seem to have popped up everywhere, except your Handheld PC.

Until recently the Sudoku puzzles were only available for other mobile platforms, but that has all changed with the release of Mobile-Sudoku 2.0 for Handheld PC by Rainer Herrler. Rainer has created an excellent version of the game, which can be played anytime, anywhere, right on your Handheld PC. A word of caution about this puzzle game; it is very addictive.

Figure 1: Mobile-Sudoku interface with Red & Blue Skin

Solving the Puzzle?

Just in case you’ve been living in a shell and are totally unfamiliar with this game… here is the abridged version of the rules for completing these puzzles. Fill in the 9x9 grid so that every row, every column and every 3x3-grid box contains the numbers 1 through 9, without duplications. It’s a simple concept but it’s not as easy as it seems to solve the puzzle.

The Many Features of Mobile Sudoku 2.0

Mobile Sudoku 2.0 has every feature that will make solving the puzzle a rewarding experience. Some puzzle solvers may enjoy using the Classic Sudoku grid, but others may wish to spice things up by using one of 5 skins available with this software. You can choose between Classic, Soil, Boys & Girls, Red & Blue and Style, I personally prefer the Red and Blue because I find the numbers easier to follow using that skin as my grid background.

Figure 2: Various Sudoku Skins available in Mobile-Sudoku

Just like the Sudoku puzzles you find in magazines and newspapers, this software provides the solver with 3 different levels of puzzle difficulty. There are 24 Heavy (most difficult) puzzles, 32 Medium puzzles and 48 Easy puzzles. If you are new to the game, then I would definitely suggest you ‘get you feet wet’ with the Easy puzzles first. Don’t worry about having to complete the puzzle in one sitting because Mobile Sudoku allows you to save an existing puzzle and reload it at a later date, as a matter of fact you can save up to 5 puzzles which are already in progress and return to them later.

If you are having difficulty solving your puzzle and would like a bit of help, perhaps a hint or two, this software provides the user with several options available in the Hint Menu. My favorite is the Show Violations feature which (can be toggled on or off) when set to ON, automatically highlight incorrect entries in red.

Figure 3: Black are existing numbers, Blue are the correct numbers and Red are incorrect additions

If you require further assistance, you might consider using the Solve Step, which randomly fills in one of the missing numbers every time you select that option. You can use it as many times as you wish, but it sort of takes all the fun out of solving the puzzle if you abuse this feature. Of course, if you are totally frustrated, you can use the Solve feature, which fills in every blank grid and essentially completes the puzzle for you.

One of the more intriguing features (from my perspective) is the Show Possibilities which (can be toggled on or off), and shows every number possibility, for every blank grid on the board. It doesn’t solve the puzzle for you, but it does take some of the guesswork out of it

Figure 4: When Show Possibilities is activated, notice the small numbers inserted into all the blank grids

If your puzzle gets really messed up, there is a Reset Puzzle feature, which restores your puzzle to its original state, but unless you are using it out of total frustration, I’m not sure what the point of doing that would be,. A more useful tool is the Undo feature, which is not really an undo feature as much as an erase your last entry feature, because it does not allow for multiple undoes.

One of the coolest (and most interesting) features is the Empty Board function, which when used in conjunction with the Compose Mode feature allows you to create your own Sudoku puzzles or use existing puzzles found in your local newspaper, magazine or the internet. What does this mean? It means that the source of Sudoku puzzles is unlimited and you are not tied to only the puzzles provided by program developer. That alone is an awesome feature!

Software Quirks and Possible Improvements

I’m happy to say that all of the features in this software seem to function as intended, but there are a few minor (easily repairable) quirks which don’t affect the functionality of the software, but are worth keeping in mind for future updates.

  • The word untitled appears in the Title Bar instead of Mobile Sudoku 2.0
  • A few of the skins have lost their grid line down the farthest right side of the puzzle grid
  • The feature boxes don’t always line up below their Titles in the Pull down Menus
  • You must hide the Taskbar in order to view the entire puzzle grid
  • The right side of the Main Menu Bar, shows either the word Sudoku or the Skin Name…….it would be nice to see either, one or the other but not a random combination of both
  • It would be nice if the Help Menu provided an explanation of the software features, but until then you can checkout my Quick Reference Guide available at

Installation & System Requirements

Installation is fairly easy, you can use ActiveSync process to automatically install the current version of the software or you can manually install the Ewe file and the Sudoku.ewe files on to your Handheld PC. The instructions on how to perform either installation method is available on the developer’s website

If you are using the Activesync process, then the Mobile-Sudoku software automatically installs into the Windows/Programs folder on your Handheld PC, but because of its size (2.2 MB+) you may wish to move it over to your CF card. Here are the steps I used to perform the move.

  1. Move the Ewe Folder to the Storage Card (contains the ewe.dll, ewe.exe etc)
  2. Move the Sudoku Folder to the Storage Card (contains the sudoku.ewe)
  3. Created a new shortcut - - \Storage Card\Ewe\ewe.exe" "\Storage Card\Sudoku\sudoku.ewe
  4. Move the shortcut to your desktop or Windows/Program folder

This software is available for HPC 2.0 and higher and for the following processors: Sh3, MIPS and StrongARM.

Final Thoughts

I am thrilled to see this software available for my H/PC and I think Rainer Herrler has created a wonderful version of Sudoku in which I’m fairly certain I’ll be playing for many, many years to come.

If you are a fan of Sudoku or if you are interested in learning this puzzle game, then I highly recommend that you try a copy of Mobile Sudoku 2.0 for HPC, I think you will really enjoy and be impressed with this software.

A trial version of Mobile-Sudoku 2.0 for HPC by Rainer Herrler can be downloaded from the developers website. As ever, if you enjoy the software, please register it, it’s well worth the $10 USD the developer is asking for it.


System Requirements:

Handheld PC 2.0 or higher
SH3, MIPS, StrongARM
2.2 MB storage space





5 Star Rating: Exceptional

Pros: Easy to use, low price, nice interface with multiple skin and puzzle choices, as far as I know, this is the only Sudoku game which is adapted to run on the Handheld PC.

Cons: There are no major cons, but see the Quirks & Improvements section as mentioned in this article.


5 Star Rating: Exceptional

Built-In helps:

1 Star Rating: Very Poor

Customer Service:

5 Star Rating: Exceptional


4.5 Star Rating: Very Good



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