The Superhuman Registration Act was a nasty business. Enacted in the Marvel Universe in 2006, it required superheroes to register themselves as weapons of mass destruction. In doing so, it caused a schism in the superhero community, with some joining behind Iron Man in support of national security, and others lining up with Captain America in defense of personal liberties. Now you'll get to choose a side for yourself. In Marvel Ultimate Alliance 2, due in September for pretty much every game console, we join our heroes on the eve of the passage of the SHRA, in an adventure that adds a social and political element to the action-RPG formula established with the previous game.

This time around, the lineup includes 24 playable Marvel characters "out of the box" -- with more downloadable or unlockable, perhaps? -- including, for the first time, villains. In the demo we were given, I saw Spider-Man, Wolverine, Iron Man, Thing, Thor, Juggernaut, Storm, Mr. Fantastic, Hulk, the Human Torch, Venom, Juggernaut, Songbird, Captain America and Deadpool (who has a habit of directly addressing the player, in what Activision promises will be a regular occurrence of breaking the "fourth wall").

It's not just neat to have so many characters, though; the way they interact is also pretty cool. In what Activision calls Power Fusion Attacks, characters can blend their powers together in new ways. We saw Hulk pick up Wolverine and throw him at a helicopter; Thor summoned a tornado that the Human Torch charged with fire; and Iron Man shot a repulsor beam into Wolverine's crossed claws, reflecting the beams all over the area and taking out huge groups of enemies.

Other additions have been made to the formula, too. The on-the-fly upgrade system has been enhanced, allowing the player to apply bonuses to the entire four-character party as well as individual characters. This makes it possible to swap out characters with none of the penalties that often appear in other RPGs.

The game engine has also been improved, allowing for many more characters onscreen to create what our demo host called "large-scale enemy encounters, on a scale we couldn't do before." And overall, the engine looks impressively sharp. Environments are detailed and diverse, with loads of destructible elements that add a feeling of realism thanks to a newly implemented physics and damage engine.

And of course, the four-character party can be controlled entirely by humans, either locally or online, which was one of the big draws of the previous game. Unfortunately, none of us humans of the journalistic persuasion were able to take control of any of the characters, so we'll have to leave hands-on impressions for another time.