From the game box:
The world's largest army of super heroes is under your control.
Assemble your ultimate four-member strike force from over 20 Marvel heroes. Become your favorite legends, then interact with more than 140 characters in this epic action-RPG.
From the Official Game Site
-Assemble your Super Heroes Create the ultimate dream team and dynamically switch team members, starting with 20 playable Marvel Super Heroes, and unlocking even more as you progress. Experience the full scale of the Marvel universe with a combined cast of over 140 characters.
-Customize your team- Use a universal team upgrade system or customize each individual member for maximum effectiveness. Total team customization means a vast selection of power-boosting equipment, a unique team name and team icon, and an established team reputation as the story progresses.
-Change the course of the game –The missions you accept, and the objectives that you meet, will have a direct impact on how the story plays out. At the end, see how your choices changed the fate of the Marvel universe.
-Fight in no-holds-barred combat. With dynamic combat capabilities, you can now fight while airborne, on the ground, and even underwater! A host of combat tactics include grappling, charge attacks and a destructible environment, where everyday objects can become dangerous weapons.
-Cooperate or compete online. Play the entire story from beginning to end individually or with up to 3 of your friends. Switch between cooperative and competitive mode to partner with or challenge up to three other players. Online multiplayer supports 1-4 people.
-Unique comic book missions that are unlocked throughout the game will reenact legendary Marvel battles.
-Over 17 exotic locales take the player around the world, out of the universe and back again.
Unique Platform Features
-PLAYSTATION®3 computer entertainment system and Xbox 360 feature amazing graphics that take full advantage of the next-gen. hardware. These include real-time shadows, detailed texture to the environments, and true hi-def. in-game cinematics.
-Nintendo Wii will have intuitive and fun Wii-specific controls for movement, combat and powers
-PC customizes the next gen. graphics to a PC with intuitive mouse controls. Incredible attack combos can be unleashed with the click of a button.
Marvel: Ultimate Alliance is an all-new Action/RPG that lets players create their ultimate team from the largest Super Hero alliance ever as they engage in an epic quest to determine the fate of the Marvel universe. For decades, Earth's Super Heroes have opposed evil in their own cities, and on their own terms. But now, Dr. Doom and a newly reformed Masters of Evil have plans for world domination, and the heroes must band together to defeat them. Players can create and control their own completely unique team, selecting from the largest roster of legendary Super Heroes ever assembled in one game.