Invincibility
Pause game play and press L(3), R(3), L(3), Start. Music will confirm correct code entry.

Level Skip
Press Start to pause game play. Press Right, Left, Down, Right, A, Start to jump to the next level.

Sound Test
Hold L + R + X + A and press Start at the option screen.

View Ending Sequence
Pause game play and press Right, Left, Down, Right, B, Start. Music will confirm correct code entry.