Zero mini-game:
Beat the game.Copy-X mini-game:
Beat the game on hard.
Fefnir mini-game:
Beat every mission with 100 points.
Leviathan mini-game:
Beat every mission with 100 points.
Harpuia mini-game:
Beat the game with only the Zet Zaber and "S" rankings.
Ciel mini-game:
Beat the game with an "S" in every mission.
Phantom mini-game:
Beat the game with only the Buster Shot and "S" rankings.
X mini-game:
Beat the game, then use the same saved file to beat the game again.
Hard difficulty setting:
Beat the game, then highlight "New Game," hold L and press Start.
Ultimate difficulty setting:
Beat the game after collecting all the hidden disks. Then highlight "New Game," hold R and press Start.
