Ultimate Sudoku Collection contains several variations of Sudoku game. Sudoku basic rule: Fill numbers in the board such that every row, column and region contains one occurrence of each number. Features: - Beginner, Easy, Moderate, Hard and Expert difficulties for every game type - Tons of puzzles guarenteed to have only one solution - Easy note taking - Autosave the process of unfinished levels - Record best completion time for each level - Hint feature - Achievements Current Game Types: - Basic - Gattai-3 - Gattai-3 Diagonal - Gattai-3 Anti-Diagonal - Butterfly - Sohei - Flower - Samurai - Samurai Jigsaw - Samurai Diagonal - Samurai Anti-Diagonal - Cross