There are 100 hidden canisters; collecting them at milestones (10, 30, 60, and 100) will permanently upgrade Hulk's health.
If you're looking for the Gladiator (Planet Hulk) skin, it is exclusive to the PS3 version and is unlocked by completing the game. The Incredible Hulk – Cheats - PlayStation 3 - GameFAQs Cheat Codes For Incredible Hulk Ps3
Defeat the U-Foes, tricking one into knocking out a teammate, and then defeat Abomination. Joe Fixit: Successfully complete the game. There are 100 hidden canisters; collecting them at
Enhance your stats permanently by searching for these hidden items: Joe Fixit: Successfully complete the game
If you prefer to earn your rewards, you can unlock these iconic skins by completing specific feats: Defeat the Abomination in story mode. Grey Hulk: Smash 10,000 objects across the city. Classic Hulk: Collect 5 comic book covers.
Destroy at least one building in every neighborhood of New York City. Professor Hulk: Complete all 15 Jump Challenges. Power-Up Collectibles