I played the beta a couple weekends ago. Like notsofast said multiple copies of the same character running around the screen. I played as the Thing and was invited to a group only to be kicked because they wanted a different Thing. It's alot like Diablo III. At least the controls are. Point and move and spam attack buttons. I made it to the first couple levels. Took down the Green Goblin fairly easy. There's some crafting thing where you make Pym particles and unstable molecules but I found it confusing and didn't want to waste my limited play time screwing with it.
This is a tough thing to pull off for these comic book companies. In DC you can't play as any existing character and Marvel there's a limited number of toons you can play. I just don't see a happy medium where they can succesfully pull this off. I played the DC version from day one for about a year and haven't picked it up since.
Videogamer.com is giving beta keys away for this weekend if anyone cares. Last weekend was better than the first one I played. It really is just Diablo with a Marvel skin. At least this way they can have expansions.