Crono put into words a lot of what I disliked about Castle Crashers and part of even why I did not much care for Scott Pilgrim, though SP is definitely the better game.
And, yes, I LOVE beat-em-ups. Castle Crashers is just not that good. It's a mindless button-masher for co-op play but getting a root canal is fun with friends so that is hardly an achievement.
Speaking of root canals, the Enslaved DLC is really good. It cuts out the combat and turns it into a light stealth shooter sort of game. The mechanics there are great and even though the whole thing screams "We cut this playable content from the main game." it has enough rework to be entertaining and, dammit, the story was entertaining as hell. Even moreso than the main Enslaved story, in my opinion.
It was a smooth ride.