Pretty good
While at its core it's just another side-scroller, the addition of rage and health regen is pretty neat. It was fun how, as you gained rage, your fundamental playing style would become slightly altered. The voice acting (what little there was) wasn't bad, though until you learn what all the moves are it's kind of confusing.
It also inspired me to make a Fury Warrior on WoW. Level 9 right now, woo.