Guilty Gear X [DC]
Get to level 20 in survival mode and Testament will appear and challenge you. Defeat Testament to unlock him as a selectable character.
Get to level 30 in survival mode and Dizzy will appear and challenge you. Defeat Dizzy to unlock her as a selectable character.
Guilty Gear mode:
Get to level 100 in survival mode or successfully complete the game using every character.
Highlight a fighter at the character selection screen. Press Start, Select, or A + X, or B + Y for more costume colors.
Successfully complete arcade mode to unlock the corresponding character's ending sequence.
Place the small bonus disc in an audio CD player that features a tray capable of playing a CD single disc. Play track two and above to hear music from the game.
Place the small bonus disc in a PC compatible CD-ROM that features a tray capable of playing a CD single disc. Two images from the game can be found in the "extra" folder.