iSudoku Game is a free Sudoku puzzle game for the windows PC. Play in Full Screen or windowed mode. drag the numbers from the left or click the cell for hints. Highlight a number by hovering over the bar on the left. Never the same puzzle twice. If you're not familiar with Sudoku, there is a common misconception that it is a math game. There is no math in the playing of a Sudoku game at all. Sudoku is a game where you have a 9x9 grid of numbers. This grid is divided up further into 9 3x3 boxes. You're goal is to fill in all the empty spaces without using the same number twice in any column, row, or grid. To make things easier for beginners, in this version of Sudoku when you click on a square, all the numbers that already appear in that column, row, or box have been crossed out.