Level select
At the title screen, hold Z and press Right, Down(2), Right. Release Z, then press Right, Up, Down, Left(2), Up, Right(2). If you entered the code correctly, you will hear a sound.

Invincibility
At the title screen, hold Z and press R(2), L(2), Up, Down, Left, Right. If you entered the code correctly, you will hear a sound.

Infinite lives
At the title screen, press L, R, B, A, Z, Left, Right. If you entered the code correctly, you will hear a sound.

All weapons
At the title screen, press Left, Right, Up, Down. Then hold Z and press Right(2), Left(2). If you entered the code correctly, you will hear a sound.

Full health and ammunition
While playing a game, press A + B + R.

Faster text
Press Z to scroll the text dialogue quicker.

Skip text
Press A to bypass the current text dialogue.