Successfully complete the indicated task to unlock the corresponding character:
- Abomination: Defeat Abomination.
- Bi-Beast: Defeat Bi-Beast.
- Grey Hulk: Smash 10,000 objects.
- Hulkbuster Iron Man: Have a saved game file from Iron Man.
- Ironclad: Defeat the U-Foes, trick a U-Foe into KOing his teammate, and defeat Abomination.
- Maestro: Destroy a building in each neighborhood.
- Professor Hulk (Smart Hulk): Successfully complete all jump challenges.
- Savage Hulk: Collect five comic book covers.