• 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

Beat the game on the normal mode to unlock Hard Mode. Hold the L Button and select New Game to activate Hard Mode.