Invincibility and Level Select
At the main screen, hold Left + Square + L1 + L2 + R1 + R2 until
"Cheat Mode" appears at the bottom of your screen. Quickly choose
Options and you can enable Invincibility or start on any level.
Triangle, Triangle, R1, Square, Triangle, R1, L2, L2, R2, R2
Pause gameplay and press Right, Square, Triangle, Square,
Nude Color Scheme
Complete the game under each difficulty setting, then win again
under Hard and enter the initials NUD.