Infinite Mode:
At the "Press Start" screen, press L1+Start for infinite mode.
Racetrack Mode:
At the "Press Start" screen, press R1+Start for racetrack mode.
Secret Characters:
To get the secret characters, do the following:
Django: finish the game as Jo.
Koji: finish the game as Lee.
Clair: finish the game as Yoko.
Vincent: finish the game as Sepiroth.
Zax: finish the game as Vincent.
Alternate costumes:
Hold Up while selecting a fighter at the arcade mode character selection screen.
Fight as Koji Masuda:
Successfully complete arcade mode using any male character.
Fight as Clair Andrews:
Successfully complete arcade mode using any female character.
Fight as Yuffie Kisaragi:
Successfully complete arcade mode as Cloud.
Fight as Vincent Valentine:
Successfully complete arcade mode as Tifa.
Fight as Django:
Successfully complete arcade mode using the eight regular non-Final Fantasy 7 characters.
Fight as Zack:
Successfully complete arcade mode using all Final Fantasy 7 characters.