I like it.

I played their free Sudoku Daily game for about a year so switching to this version was a natural. The interface was a little awkward until I got used to it, but I do like the fact that the puzzle fills up as much of the screen as possible (making it easier to read). The sound effects are annoying as heck, so I shut them off a long time ago. The main selling point for me is the puzzles [on the clinically insane level] are tough and the puzzles in this version are considerably tougher than those in Sudoku Daily.

Kae Arby about Sudoku Unlimited