Enter at main menu:

Invincibility:
Press L, R, L, R, L, R, L, R at the main menu. A message at the bottom of the screen will confirm correct code entry.

Exploding fists:
Press R(2), Y, B, X, R(2) at the main menu. A message at the bottom of the screen will confirm correct code entry.

Hot fists:
Press L(2), X, B, Y, L(2) at the main menu. A message at the bottom of the screen will confirm correct code entry.

Exploding bullets:
Press L, R, Z, Y, B at the main menu. A message at the bottom of the screen will confirm correct code entry.

Flame on:
Press X, Y, B, X, Y, B at the main menu. A message at the bottom of the screen will confirm correct code entry.

Level select:
Press X, Y, Z(2), X, Y, Z(2) at the main menu. A message at the bottom of the screen will confirm correct code entry.

Liquid metal textures:
Press B, Y, X, B, Y, X at the main menu. A message at the bottom of the screen will confirm correct code entry.

Big heads:
Press R(2), L, R at the main menu. A message at the bottom of the screen will confirm correct code entry.

Small heads:
Press L(2), R, L at the main menu. A message at the bottom of the screen will confirm correct code entry.

Pin heads:
Press B, X, Y, B, X, Y at the main menu. A message at the bottom of the screen will confirm correct code entry.

Slower enemies:
Press B, X, Y, Z, L, R at the main menu. A message at the bottom of the screen will confirm correct co