Sudoku Pro-Free puzzle game
The most Professional Sudoku game is coming!
With four different degrees of difficulty and more beautiful frames.
Try and beat other chanllengers arround the world!
Rules: use 1 to 9 to fill the 9 * 9 board, so that each row, each column and nine groups of 3 * 3 small checkerboard all contain the numbers 1 to 9