Was 5 stars but some of the puzzles get so frustrating at higher levels that you want to smash your phone. The game was very fun early on but as you progress the level design is either poorly done and lazy or specifically designed to force you to spend money and I'm not sure which is worse. Edit: lowered to 1 star because this game is so frustrating. Also, the developers admit in their response that this is a pay to play game. More frustrating than fun.