Sudoku Game is a free puzzle online game for boys, with various styles of backgrounds for you to choose from freely. The game has classic rules, multiple modes, and challenges of different difficulty. You can choose the difficulty to challenge according to your own level, and you also can take notes at will in pencil. Are you ready for a master challenge? Come and enjoy this puzzle game! Sudoku, game, online, puzzle, boys, brain training, free, Android, HTML5, kids, number, challenge, fun, highscore, online game, puzzle game, boys category, difficulty levels, background customization