I really like the puzzles in this game--you have to really think through the order in which you get the keys, if at all! The art and effects are also great, and there is so much polish. My only complaints are that the screen shake is too intense, and it can be frustrating if you grab the wrong key (I'm mainly talking about the key in the last level in the upper right corner) and have to restart all the way from the beginning. Pretty solid submission though!