Pretty well-made puzzle game, even with several different modes unlocked after you finish the main game.
Many levels were more about fast and accurate clicking rather than solving a puzzle, though.
Perhaps you could add a medal unlocked when you complete the game, too. It'd be a good metric also for you to see how many people started – and how many of that finished your game.
Oh, by the way, you ought to also write *yourself* in the Credits section, not just the music tracks used. :)