Really impossible 'puzzles' that are so frustrating to drive you to hit that skip button...wait that skip button is huge and next to it a very tiny butto with an arrow on it...that's the go back button. Let's say i started with 15 coins and I kept hitting that skip (also masquerades as the hint button). So no coins in no time before you hit one of those impossible puzzles..and you can't solve it and you can't skip it until you fork out real money. Oh well, what do your expect from a 'free' game?