Chains Sudoku is simple sudoku game with new feature: only unique numbers in cells of same color."Sudoku (數(shù)獨(dú) sūdoku) Listeni/su??do?ku?/, originally called Number Place, 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 sub-grids that compose the grid (also called "boxes", "blocks", "regions", or "sub-squares") contains all of the digits from 1 to 9. The puzzle setter provides a partially completed grid, which for a well-posed puzzle has a unique solution.Completed puzzles are always a type of Latin square with an additional constraint on the contents of individual regions. For example, the same single integer may not appear twice in the same 9×9 playing board row or column or in any of the nine 3×3 subregions of the 9×9 playing board." WikipediaThere are no subregions in Sudoku Chains - only color chains with the same purpose.Addictive puzzle with the spirit of 2048 but more ancient and epic.