When the warning appears on the opening screen, press Square + Triangle + Circle + X. Then, four players may play the game simultaneously.
Hint: One-hit kill
Select Captain or Jennety as a character. Hold X + Circle, and press Special Move to execute a one-hit kill.
Stage select
Highlight the "Game Start" option, then press X + Circle + Left. The starting stage number will appear next to that option to confirm correct code entry.