Gex

First pause the game and press and hold R1, then enter any of the following codes with R1 held:

Effect:          Code:
Infinite Lives - UP, Circle, Triangle, DOWN, RIGHT, Square, DOWN.
Ice Weapon     - Circle(x2), LEFT, DOWN, Circle, UP, RIGHT.
Super Jump     - X, Circle, UP(x2), DOWN, RIGHT(x2).
Fire Balls     - X, UP, RIGHT, UP, RIGHT(x2).
Invincibility  - X, Square, DOWN(x2), UP, DOWN, RIGHT.
Electricity    - RIGHT, LEFT, RIGHT, Circle, Triangle, RIGHT, Circle, DOWN, RIGHT.

 