Sudoku (数独 sūdoku, digit-single) - is a logic-based, combinatorial number-placement puzzle. The objective is to fill a 9×9 grid with digits so that each column, each row, and each of the nine 3×3 subgrids that compose the grid (also called "boxes", "blocks", or "regions") contains all of the digits from 1 to 9. 
-  150 brain-teasing Sudoku puzzles
 
-  Random level generator
 
-  Level's progress save
 
-  Beautiful minimalist design, multiple color themes
 
-  10 ambient relaxing soundtracks
 
-  Achievements with Latin and Cyrillic characters
 
-  Trading Cards, Badge, Emoticons and Backgrounds
 
-  Steam Cloud support