Enter these codes in the cheat menu (in the 'special' menu)

All Levels + Movies = ARACHNID
Get Super Coolant = CHILLOUT
Get Big head mode = JOELSPEANUTS
Unlock All-Fighting Controls = KOALA
All Production notes + some Movies = IMIARMAS
Get Character Scientist = SERUM
Get Character Shocker = HERMANSCHULTZ
Get Character Mary Jane Watson = GIRLNEXTDOOR
Get Character Thug 1 = KNUCKLES
Get Character Thug 2 = STICKYRICE
Get Character Thug 3 = THUGSRUS
Get Character Matrix Spidey = FREAKOUT
Get Character Helicopter Pilot = CAPTAINSTACEY
Get Character Police Officer = REAL HERO
Get Matrix Attacks = DODGETHIS
Get Unlimited Webbing = ORGANICWEBBING
Get Next Level Feature in in-game menu = ROMITAS
Get 1st Person Mode = UNDERTHEMASK
Get Extra Training Levels = HEADEXPLODY
Get Big Head & Feet Spider-Man = GOESTOYOURHEAD
Get Tiny Spider-Man = SPIDERBYTE