3 stars: The game itself is perfect. Layout and graphics are better than any other sudoku app. The inescapable video ads, though, are driving me crazy. And you can't upgrade, so you're stuck with the ads.
5 stars: This game is not too complicated to play but does take a great deal of concentration and attention to detail. The option to make notes in the squares helps to make a very challenging game doable! I'm midway through level four and haven't encountered any mistakes in the game that would make the level unsolvable but I have made mistakes I've had to backtrack to fix.
5 stars: Really enjoy the game. Entire effort is well executed. There is a bug in timing the games however. If you pause a game, and resume it the next day but at an earlier hour, the elapsed game time is absolutely wrong. It only affects statistics, not the play, so no big deal. Just a minor annoyance.
5 stars: good product, i miss an option to completely reset the game to the start value. just changed my opinion from 4 to 5 stars, this is because the developers responded almost instantly. perfect show of support.
3 stars: Hard to play mainly because the controls are very rudimentary. For example, how about a one touch control to fill a square with all numbers? Numbers at the bottom the page are dark and hard to read. It's difficult to make out which numbers are complete.
5 stars: I think it was my phone causing problems with this game. Not sure. I still play this game just being extra...