Pause the game, and then hold L2 while pressing the following buttons:

Invincibility - RIGHT, RIGHT, LEFT, RIGHT, LEFT, LEFT, RIGHT, LEFT, R2, UP, UP, DOWN, DOWN, UP, DOWN, UP, DOWN, R2.

99.9% dose - R2, R2, LEFT, RIGHT, UP, DOWN, RIGHT, LEFT, UP, DOWN, TRIANGLE.

Max red weapon power - R2, R2, LEFT, RIGHT, UP, DOWN, RIGHT, LEFT, UP, DOWN, SQUARE.

Max yellow power - R2, R2, LEFT, RIGHT, UP, DOWN, RIGHT, LEFT, UP, DOWN, X.

Max blue weapon power - R2, R2, LEFT, RIGHT, UP, DOWN, RIGHT, LEFT, UP, DOWN, CIRCLE.