I noticed Peter and Link also bought this game on Steam when it was like 75% off, and basically I FUCKING love it's tons of fun. It's a really unique and interesting concept on Tower defense types. I think Dungeon Defenders is a similiar type of game only it's based on Multiplayer. I'm hoping that goes on sale this steam fall sale since I'm enjoying Orcs Must Die.
http://www.youtube.com/user/SSoHPKC#grid/user/F1C6DC58C7DA9E84
SeamusPKC's Play through of the game. If anyone is interested, he is also doing a Skyrim play through.