$15 bucks is a little steep, even for a great co-op game like Dungeon Defenders. Have you been waiting to take the plunge? Well all your hard work (sitting idly by and doing nothing) has paid off. Dungeon Defenders is 800 MSP ($10) on the XBLA. It's part of the LIVE Arcade's Deal of the Week, so you'll have until January 17th to make up your mind.
We gave Dungeon Defenders a 5 out of 5 for our Co-Op Review. You can see the launch trailer here. It supports four player online co-op, four player local co-op, and four player combo co-op.