Play as Dark Buffy in Arena
To see what it's like to play as evil Buffy (if only in Arena mode), go to the Extras screen and enter this code: BLACK, WHITE, Y, Y, BLACK, BLACK, WHITE, BLACK, BLACK, WHITE, BLACK, BLACK, WHITE, BLACK, BLACK, BLACK, WHITE, WHITE.
To unlock new arenas, go to the Extras menu and press Y, Y, WHITE, BLACK, BLACK, Y, Y, Y, Y, Y, WHITE, BLACK. You will hear a scream and four Arenas will show up on the screen