3Doku for Android

The puzzles are nearly impossible to solve at hard and above without enabling all options. However, manually removed hints cannot be undone, which means you can make a mistake and never get back to a valid puzzle using the undo button. Also, the auto fill function rarely fills all the cells left with only one hint, which can be annoying. Nobody would want to try to fill in several hundred numbers by hand. This should be fixed. Finally, the cube graphic showing initial, solved, and current cells will never update on Mobile 3 with iOS 5 until you rotate the screen orientation. However, if you have plenty of time, these hard puzzles take some work to solve, and the Monster puzzles are nearly impossible without advanced solving techniques like fish and inference chains. Once the above problems are fixed, I will re-rate this as five stars.

As with all derivates of Sudoku that try to "complicate" the game, they make the game actually easier to solve since they add more restrictions to each layer. So, while in an ordinary Sudoku, each cell has 3 restrictions, in this version, it gets two additional sets of 3 restrictions from the two other layers that the cell is intersecting with. Now this is not to say that it is not a fun thing, as it makes the game a lot longer to manually solve, since you have like 729 cells to fill. Bottom line: recommended, but not for complexity, but for length of play. M P.S. While reviewing the more difficult levels, I see that the game offers levels where every single layer cannot be solved on its own, i.e. you don't find one single cell that's not unambiguous. In addition, the "wrong cells" counter does not count cells that were wrong but did not have any conflicts so far, which is great as you may well be heading the wrong direction for hours and you cannot simply guess. These two aspects make the game a lot harder to solve on any non- novice level than initially thought, which makes it have a clear added value over a simple 2D sudoku. Hence, a clear recommendation.