Enter the following at the Options/Code menu, then activate them at the Options/Special

Features/Cheats menu.

GMMSKIN      Invincibility

TRUBLVR      All Levels 
FLSHWND      Regenerator 
ANGMNGT      Rage Meter to Max 
GRNCHTR      Unlimited Continues 
HLTHDSE      Double HP 
BRNGITN      Double HP for Enemies 
MMMYHLP      Halve HP for Enemies 
FSTOFRY      Killer Punch 
BRCESTN      Solve Puzzle 
NMBTHIH      High Score Reset

Enter the following at any terminal in the game:

JANITOR      Play as Gray Hulk
SANFRAN      Hulk Transformed movie art
PITBULL      Hulk vs. Hulk Dogs movie art
FIFTEEN      Desert Battle movie art
NANOMED      Hulk Movie F/X movie art
   
   

Thanks to Revolution readers Stealth and Peter!