This game is great because of its budget price, replay value, and, most of all, great puzzle gameplay.
There are two different modes: Normal and Free. Normal adds two minutes to the total time amount for mistakes, but free does not. It's similar to playing sudoku on the computer against playing it on paper. Normal puzzles are usually easier than free ones, at least to me.
There is also a wi-fi challenge mode, which is really addictive. It provides two 10 x 10 puzzles for the players to solve, and the first to solve them wins. Guessing is an option if the puzzle is very hard, but you will be penalized 5 seconds if you are wrong. It is definitely worth guessing on the harder puzzles. The only problem with this mode is that the matching tends to be unbalanced sometimes, and the champions or advanced people tend to be much too fast. This problem can be solved, however, by playing with your friends.
The wi-fi challenge mode is not the only use of wi-fi, however. Nintendo will provide puzzles from other, older picross games for you to download at some point.You can also download other user-created puzzles if you trade friend codes with the creators. You both have to go online (not at the same time) to get access to their puzzles or for them to get access to yours. The creation mode is also decent. First, the final picture has to be drawn. Then, there is a transparent view that can come on the screen to show which squares to fill in. The final picture will be in color, but the puzzle will not. There is also no animation like there are for the built-in puzzles.
Lastly, daily picross is much like the daily tests of Brain Age. There are five different types of challenges to do.
Overall, Picross DS is an amazing game for those that like puzzles and want something cheaper.