Go to the codes screen and enter this phrases to unlock the corresponding cheat
All Areas Unlocked: BEAMMEUP
All FMVs Unlocked: HOTTICKET
All Gadgets Unlocked: TINKERTOY
All Morphs Unlocked: EUREKA
Don't Take Damage: CHEATERBOY
Invincibility: NECROSCI
Secret Morphs Unlocked: LOGGLOGG
Super Ending: BUZZOFF
