Ikaruga

Additional credits:
Accumulate at least three or four hours of total game play to get additional credits. By the time you have accumulated six hours, you should have about nine credits from the start, but it is not unlimited.
Information in this section was contributed by ikonos.

Gallery 1 option:
Successfully complete trial mode without using any continues to unlock the "Gallery 1" option at the "Appendix" menu. Alternately, accumulate at least five hours of total game play.
Information in this section was contributed by wruesch.

Gallery 2 option:
Successfully complete the game under any difficulty setting to unlock the "Gallery 2" option at the "Appendix" menu. Alternately, accumulate at least ten hours of total game play.
Information in this section was contributed by wruesch.

Sound test option:
Successfully complete the game under the easy difficulty setting without using any continues to unlock the "Sound Test" option at the "Appendix" menu. Alternately, accumulate at least fifteen hours of total game play.
Information in this section was contributed by wruesch.

Game mode option:
Successfully complete the game under the normal difficulty setting without using any continues to unlock the "Game Mode" option at the "Appendix" menu. Alternately, accumulate at least twenty hours of total game play.
Information in this section was contributed by wruesch.

Hidden artwork:
Place the game disc in a PC compatible CD-ROM drive to find BMP images from the game.
Information in this section was contributed by wruesch.