Alternate costumes and more options:
Successfully complete single player mode under the normal or higher difficulty setting. Highlight a fighter and press Down at the character selection screen to choose a new costume. Additionally, the number of continues and rounds may now be adjusted in the options screen.

Slow motion replay:
Hold Circle before the replay begins.

Play as Boss:
Successfully complete the game using all ten characters. Press Left at the leftmost or Right at the rightmost fighter at the character selection screen.