Beat the game to unlock Zero's mini-game. A Mini-games menu should appear at the title screen, and you can select it from there.
Complete all missions with 100 points: Fefnir Mini-game
Use Zet Zaber for the whole game and beat the game with S rank: Harpuia Mini-game
Complete every mission with 100 points: Leviathan Mini-game Use the buster shot for the whole game and beat it with an S rank: Phantom Mini-game
Ciel mini-game:
Successfully complete the game with an "S" rank on all missions.
Copy-X mini-game:
Successfully complete the game under the hard difficulty setting.
Fefnir mini-game:
Successfully complete all missions with 100 points.
Harpuia mini-game:
Successfully complete the game by only using the Zet Zaber and get an "S" rank.
Leviathan mini-game:
Successfully complete all missions with 100 points.
Phantom mini-game:
Successfully complete the game by only using the Buster Shot and get an "S" rank.
X mini-game:
Successfully complete the game, then use your cleared saved file to complete the game a second time.
Zero mini-game:
Successfully complete the game.
Hard difficulty setting:
Successfully complete the game, then highlight the "New Game" option at the main menu, hold L and press Start.
Ultimate difficulty setting:
Successfully complete the game after all the hidden discs have been collected. Then highlight the "New Game" option at the main menu, hold R and press Start.
