Gradius Gaiden Codes -

Power-up:
Pause game play and press Up(2), Down(2), Left, Right, Left, Right, X, Circle. A sound will confirm correct code entry. Note: The code may only be enabled once per level.

Level select:
Complete the game without using any continues under the normal difficulty level. A level select option will appear on the title screen.

Free play mode:
Accumulate at least ten hours of game play under any difficulty level, then save the game. Restart the game to access free play mode.