The puzzle phenomenon of Sudoku comes to the PSP in Go! Sudoku. Pen and paper is no longer required as the game comes pre-loaded with 1000 Sudoku puzzles, with the option to download additional puzzles from the game's website.
The actual game of Sudoku is fairly simple, and has nothing to do with mathematics at all - instead, it's all to do with logic. The numbers one to nine must fit horizontally and vertically in the 9x9 Sudoku grid - the catch is that the numbers one to nine must also appear in each of the nine smaller 3x3 grids.
The game features a short tutorial that shows you how to play, as well as a Training option which lets you play five easy puzzles with help. Multiplayer mode is also supported either by taking turns with one system (either co-operatively or competitively), or by playing wirelessly with up to four PSPs.