Music test:
Successfully complete the game under the easy difficulty setting to unlock the "Music Test" option at the configuration screen.

Hard difficulty:
Successfully complete the game under the normal difficulty setting.

Toggle subtitles:
Successfully complete the game under the normal difficulty setting. An option to toggle Japanese subtitles during the intermission sequences will be unlocked at the configuration screen.

Frame skip:
Successfully complete the game under the hard difficulty setting to unlock the "Frame Skip" option at the configuration screen. Enabling this option will reduce slowdown during the game.

Game speed:
Successfully complete the game under the hard difficulty setting to unlock the "Game Speed" option at the configuration screen. Set this to ''Turbo'' to play at double speed.