Sudoku is the puzzle phenomenon from Japan, a game that looks like a math problem, but is in fact a twisting puzzler. The rules are simple: start with a grid consisting of nine three-by-three squares in which some of the numbers are already supplied. Fill in the blank squares so that each column, row, and three-by-three grid contains a number from 1 to 9 with none repeated.

The Sudoku PSP game game features a thousand puzzle problems (plus the option to download more later), tutorial and training modes as well as an in-game help, and multiplayer options that include pass play, VS, battle, collaborative play, and even Game Sharing.