I have not played Castle Crashers, but word on the street/net is that it's a very good game. It's a beat 'em up in the vein of Knights of the Round. The fact that it comes from developer The Behemoth, the same folks who brought us the excellent Alien Hominid is more than enough to make me take interest in the title. I just found out that the soundtrack is available for a free download at New Grounds. So if you like free video game tunes (who doesn't?), enjoy.
Castle Crashers mp3 tracks