Select special on the Main menu and then cheats and type in XCLSIOR.

Select special on the Main menu and then cheats and type in RUSTCRST.

Select special on the Main menu and then cheats and type in STRUDL.

Enter the following as codes at the 'Specials' Menu. Enter the code again to turn it off.

ARACHNID Master code
CAPTAINSTACEY Play as a helicopter pilot
CHILLOUT Super coolant
DODGETHIS Matrix-style attacks
FREAKOUT Play as Matrix Spider-Man
GIRLNEXTDOOR Play as Mary Jane
GOESTOYOURHEAD Big head and feet for Spider-Man
HEADEXPLODY Bonus training levels
HERMANSCHULTZ Play as The Shocker
IMIARMAS Level Select
JOELSPEANUTS Enemies have big heads
KNUCKLES Play as thug 1
KOALA All fighting controls
ORGANICWEBBING Unlimited webbing
REALHERO Play as a police officer
ROMITAS Level Skip. Pause game and select "Next Level"
SERUM Play as a scientist
SPIDERBYTE Small Spider-Man
STICKYRICE Play as thug 2
THUGSRUS Play as thug 3
UNDERTHEMASK First person view

Beat the game on Normal. The costume can be found at the 'Specials' menu.

Beat the game on Easy. The costumes can be found at the 'Specials' menu.

Beat the game under Hero or Superhero difficulty to unlock the Green Goblin costume at the 'Specials' menu. You can then play through the game as Harry Osborn. An easy way to do this is to enter the ARACHNID cheat. Use "Level Warp" to go to the conclusion level. Watch the cinematic, the get back to the main menu and enter the "Specials."