All Weapons
Pause gameplay and press Up, Up, Down, Down, L, R, L, R, B, A.
Challenge B mode
Successfully complete the game in Challenge A mode.
Challenge A mode
Successfully complete the game to unlock the ''Challenge A'' option at the main menu.
Delete saved game
Enter the options screen, highlight "Exit", then hold L + R + B and press Start.
Self-destruct
Press Start to pause game play, then press Up(2), Down(2), Left, Right, Left, Right, B, A, Start.
All power-ups
Press Start to pause game play, then press Up(2), Down(2), L, R, L, R, B, A, Start. Note: This can only be done a limited number of times until it causes your ship to self-destruct.
Alternately press Start to pause game play then press Down(2), Up(2), Right, Left, Right, Left, A, B, Start. This code can be done as many times as needed, but costs one life. Additionally, it does not provide the Speed power-up.