It's free, if you haven't already downloaded it, get it. I've only played two levels thus far, but the game is fun. And has a very quick level/item progression with a coop mode that seems like it could be quite fun.
The player speak seems a bit fuzzy, but that could just be Trev's microphone.
Did I mention it is free? All you have to do is sign up for steam, and I know that a bunch of you already have it. Oh and steam is free too if you don't have it.