Sudoku on its own is a very complex game. All but the most mathematically inclined put extensive mental energy forward to complete even moderate Sudoku puzzles. So the very concept of changing the game to use something other than numbers is enough to cross the eyes. But Deca Color Sudoku manages to do it right, presenting an engaging, mind-bending variation on the classic puzzler that works well.
The idea is very simple. Instead of nine numbers, Deca Color Sudoku uses nine colors. The same rules as traditional number-based Sudoku apply: match up the colors across all 18 rows and columns so that none are in the same straight lines. It takes careful thinking and the acquired ability to visualize multiple outcomes at once. More importantly, color-based Sudoku requires a very different kind of perception than number-based Sudoku. Those who are more visually oriented may find this version more immediately accessible, while those who excel in the number-based puzzles might find the color-based patterns much harder. The game, itself, is well structured, there are hundreds of puzzles, and you can save your scores for future reference.
The free version of Deca Color Sudoku is immediately accessible, feature-rich, and easy to play. You can pay for the upgrade if you finish all of the dozens of free puzzles, unlocking up to 300 total puzzles, but if this is the case, you are clearly getting a lot of use out of the app. This is a very good app, filled with content that is engaging and unique to the Sudoku niche -- a must try for anyone who enjoys their morning puzzles.