So far it's okay, its definitely not up there with Mass Effect as a good RPG though. The voice acting is a bit off with some characters. I think a few of them are from marvel cartoons such as wolverine and the avengers (I think they're from the last xmen cartoon they had and the ultimate avengers movies).
The original team is more fun than the other one I got going. I like playing the discs you pick up that have key moments in the lives of characters on them. The only voice that really doesn't seem right to me is Deadpool's, I always imagined him more of a Mark Hamill JOker-like voice.
I enjoyed it but its key you don't think of it as a RPG more a beat em up with RPG elements thrown in. I just enjoyed teaming up ccertain characters for fun like thor and daredevil.