Cheat Codes:

Code - Result
NECROSCI - Invincibility
TINKERTOY - All Gadgets
EUREKA - All Morphs
CHEATERBOY - Never Take Damage
LOGGLOGG - Secret Morphs
HOTTICKET - View FMVs
BEAMMEUP - Go Anywhere
BUZZOFF - Super ending

Easy Isotopes
Zap the television in Muto's house to get 10 Isotopes.