Unlock Dural Highlight Akira if you are using controller one or Jacky if you are using controller two. Then press Left and then Right on the D-Pad. Keep repeating this a few times and Dural will appear as a selectable character.
Unlock Alternate Costumes: Hold 'Up' and then select your character with the A or C button.
Unlock Extra Character Selection Time: At the 'Character Selection' Screen press Down, Up, Right, and A + Left for an extra 99 seconds of time.
Unlock Hidden Options: At the 'Options' screen highlight 'Exit' and keep tapping Left repeatedly until another Options menu appears.
No Damage: At the 'Options' screen hold B while highlighting player 1's life selection until the message 'No Damage' appears. Then press Start.