Code Terminal Cheats:
Enter these cheats at a code terminal in the game:

Play as Gray Hulk                 JANITOR
Unlock Desert Battle art          FIFTEEN
Unlock Hulk Movie FMV art         NANOMED
Unlock Hulk Transformed art       SANFRAN
Unlock Hulk vs. Hulk Dogs art     PITBULL

Code Input Screen Cheats:
Enter these cheats at the code input screen in the Options menu:

Full Rage Meter                   ANGMNGT
Double Health for Enemies         BRNGITN
Double Health for Hulk            HLTHDSE
Half Enemies' HP                  MMMYHLP
High Score reset                  NMBTHIH
Invincibility                     GMMSKIN
Level Select                      TRUBLVR
Regenerator                       FLSHWND
Unlimited Continues               GRNCHTR
Wicked Punch                      FSTOFRY
Puzzles Solved                    BRCESTN