Here are some cheats and tips for the game Gradius.
Full power-up:
Pause game play and press Up(2), Down(2), Left,
Right, Left, Right, B, A, Start
for missiles, items, and shields. Note: This may only be done
once per level.
Continue game play:
Quickly press Down, Up, B, A,
B, A, B, A, B, A after
losing the last ship on level two or higher.
Level skip:
Destroy the ship that appears at the end of each level within
five seconds to skip the next level.