Gaiares

Invincibility:
Pause game play, then hold A + C and press Left. The screen will freeze for a moment. Resume game play to be invincible for the remainder or the level. Note: This code may only be enabled at the start of each level.

Cheat mode:
Hold A + B + C + Start at the title screen to enter configuration mode. Set the sound test value to 18. Hold A on controller two and exit configuration mode. Enter the following controller actions to enable the corresponding effect.

Level select
Press Start at the title screen to display the level selection screen.

Weapon select
Pause game play. Hold Up and press A to select a weapon.

Full power
Pause game play. Hold Up and press A(2). Resume game play and fire the TOZ.

Super weapon:
Fire the TOZ completely six times, then capture an enemy ship that normally awards a weapon. The T-Braster, a weapon with heat-seeking capability, will be available for use.

Bonus level:
Fire the TOZ 128 times.