• Adjust brightness

Enable the "Sound test" code. Press Select, Up, Up, Down, Down, Left, Right, Left, Right, II, I at the sound test menu. | [Sent by Neto]
  • Final Boss battle

Hold Down + I and press Run at the "Input your birthday" screen. | [Sent by Neto]
  • Mini-game

Enable the "Adjust brightness" code. Press Select until a flashing red screen appears. Then, press II, Up, Up, Down, Down, Left, Right, Left, Right, II, I. Use the D-pad to move, II to shoot, and I to fire a smart bomb during the mini-game. | [Sent by Neto]
  • Monochrome mode

Press Select fifteen times in level one during game play. Press Run to pause game play, then hold I and press Up. | [Sent by Neto]

  • Sound test

Hold Up + I and press Run at the "Input you birthday" screen to display the sound test menu. Note: The duration that Run must be pressed is very precise. | [Sent by Neto]
  • Unlimited extra lives

Pause and resume game play one hundred times. All enemies that are shot will turn into bonus lives. | [Sent by Neto]