Toon-Doku is based on the faulty premise that since playing Sudoku involves no math, you can just replace the numbers with pictures of anything. While it's true that the ubiquitous puzzle game does not require any math skills, it does involve a lot of counting, and numbers tend to work better than fruits and vegetables when it comes to counting. The key to playing Sudoku is looking at a group of numbers and being able to ascertain which one is missing. If you're looking at a 3x3 grid of symbols and see a slice of pizza, an ice cream cone, a can of soda, a peach, a banana, a baseball, a smiley face, and a toucan bird, it's a lot more difficult to identify the panda as the missing symbol.

Toon-Doku is packed with features, like over 200 different symbols (most of which must be unlocked), a symbol editor, wireless symbol trading, etc. All of these are worthless in light of the above fallacy. The only nine symbols worth using are the ones depicting Arabic numerals 1 through 9, making the core gimmick of this game completely irrelevant.

The other so-called innovation of Toon-Doku is that you choose an avatar character (including ones named "Boy" and "Girl") and occasionally play boss battles. The only difference between normal puzzles and boss battles is the distraction system, in which the two characters toss junk at each other to cover up sections of each other's puzzle, which must be manually cleared off. You attack the opponent by dragging a number (or symbol, if you woefully avoid my advice) to match the one currently shown on the distraction launch pad. This whole mechanic doesn't make the puzzles harder to complete, just a lot more annoying because you have to stop thinking about Sudoku every couple of minutes to throw more crap at the other character. Yes, it is very distracting… now who thought that would be a good thing to add to this game? How many people are out there playing Sudoku in their morning newspapers, thinking how much better the puzzle would be if only someone would intrude every minute or so to distract from all that pesky thinking?

Ostensibly, all of the symbol stuff was implemented to better suit children who might be intimidated by the numbers. But guess what: if you're too young to handle numbers, you probably have neither the patience nor the logic skills to solve most of the 100 puzzles included in this package. Regardless of your age, you'll be frustrated before long – I was unable to solve the second boss puzzle after four consecutive attempts. This happened on a set of puzzles labeled "Very Easy", and this is hardly my first exposure to Sudoku. That's not even considering the controls, which span fifteen pages of text in the game's tutorial.

Toon-Doku is certainly an ill-conceived variation on a popular formula, but I have to question why anyone would want to play Sudoku on the DS in the first place. Why would you want to spend twenty or thirty dollars and deal with battery life and interface problems when you could pick up a book of Sudoku puzzles for five bucks and play it anytime, anywhere, and completely on your own terms? The only good implementation of Sudoku on the DS is in Brain Age, and Nintendo was smart enough to include it as a side-attraction, not as its own game, because it's not worth buying on its own. Therefore, Toon-Doku is even less worthwhile; in fact, I really can't recommend it to anyone at all.