So didnt see a thread for this (if I missed it, point me too it!)
Never played the first one but this 2nd one looks awesome. It appears to be the events of the Marvel civil war. SO basically you form a team and fight other superheros.
Pro-Reg is Ironman and Mr. Fantastic
Anti-Reg is Capt. America and Luke Cage.
You pick a side and recruit other marvel heroes like deadpool, spiderman, human torch, etc. It also appears to be a 4 player co-op game, making me think of the old Ninja Turtle arcade game were you and 4 buds fight baddies on a map together. Looks like an interesting game and it releases next week.
http://marvelultimatealliance.marvel.com/