When fighting as Flynn with very low life, face right, hold R, and press Down, Down/Right, Right, X. Flynn will turn red and gain extra power.
Fight as Same Character
Highlight the "1P Game" option at the title screen and hold L + R + Down on controllers one and two. The "2P Game" option should automatically become highlighted. Press Start on controller one. Both players may now select the same character for game play.
Hold L + R + A at the Jaleco logo screen. Release the buttons when the "Press Start" text is displayed. Nortin and Orbot will be available on the character selection screen.
Super moves at any time
When playing as Flynn, Echo, or Prokop, grab an opponent from the front. Sweep the D-pad in a Half-Circle towards the direction your character is facing and press the Attack button to execute the super attack. For Norton or Al, execute the same motion when you grabbing your opponent from behind.