Extreme Sudoku is an ideal, online, free puzzle game that will be interesting for both beginners and advanced users. If you like math games and logical games, this game will suit you well. To say it brief, if you are not familiar with the rules, you can familiarize yourself with it before the game starts. They are quite simple and master the game will be easily and quickly. In free cells you will need to insert a number from one to nine which will be used once. The main thing is that there are no horizontally and vertically repetitions, as well as in 3 by 3 squares. So keep an eye on your large nine by nine square, see all numbers in small squares and be very attentive and logical in such an interesting puzzle game as Extreme Sudoku!