Pretty poor entry into the series. It's not very well balanced, in terms of being able to properly level up the characters you want to use. You essentially can't pick characters you like, and use them through out the game. They will never be powerful enough, as the story progresses. You are almost forced to use the new characters you pick up through storyline progression. For example, a new character I just got, is level 26. Most other characters, from the beginning, are around level 15/16. And grinding isn't even that realistic, as the game is painfully linear.
The game feels lazily and hastily put together. Pretty huge disappointment for me. Maybe worth playing, if you can get it for $20 or less. But I'd save my money, and buy almost anything else.
Overall, 5/10. And that's only because I love Marvel and the art style is cool to look at.