This game is similar to sudoku, except that there are extra 3x3 regions where the numbers must not repeat. In this game there is a grid of 9 x 9 squares, you need to fill in each square with numbers 1 - 9 so that the numbers in each row or column or each 3 x 3 group (the 9 groups surrounded by thick lines plus the 4 groups with dark background) do not repeat. The faster you finish the game, the higher your score. Click the hint button when you are stuck, but you will suffer a time penalty when you do so.
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.