Huge amount of different types of Sudoku games in one game. Click on a cell you want to place a number in and then on the number that appears in a ring.
How to play sudoku games:
There is really only one rule to Sudoku: Fill in the game board so that the numbers 1 through 9 occur exactly once in each row, column, and 3x3 box. The numbers can appear in any order and diagonals are not considered. Your initial game board will consist of several numbers that are already placed. Those numbers cannot be changed. Your goal is to fill in the empty squares following the simple rule above.