Code - Result:
111111 - Unlocks Iron Man and War Machine
222222 - Unlocks Hulk, Grey Hulk, and Red Hulk
333333 - Unlocks Wolverine, his brown costume, and Feral Wolverine
444444 - Unlocks Thor, Chain Armor Thor, and Loki Thor
555555 - Unlocks Silver Surfer, Anti Surfer, and Gold Surfer
666666 - Unlocks Falcon and Ultimates Falcon
777777 - Unlocks Cheat- Super Knockback
888888 - Unlocks Cheat- No Blocking
999999 - Unlocks Doctor Doom, Ultimates Doom, and Professor Doom
246246 - Unlocks A.I.M. Agent/ Blue Suit A.I.M. Agent
925627 - Unlocks Captain America and US Agent (Wal-Mart version only)
925678 - Unlocks Spider-Man and Symbiote Spider-Man (Wal-Mart version only)