Hold 5 + J + V + [Esc] + [F2] + [Right Alt] + [Help] + [Ctrl] + [Keypad (] + [Keypad Enter] + [Space] at the title screen. The bottom of the title screen will turn purple to confirm correct code entry. Press one of the following keys during game play to activate the corresponding cheat function.
More energy for player one
More energy for player two
Alternatively and repeatedly press 1 followed by 2 at the continue screen when "1" appears after the word credit. Keep pressing the keys through the prompt to change disks until both men drop from the top of the screen.
To enable this code, press Down, Down, Left, Right, Up, Up from the Difficult Select menu. To use it, press LS while fighting to kill your opponent.