Hold down '5', 'J', 'V', 'ESC', 'F2', 'RIGHT ALT', 'HELP', 'CTRL', , '(' (numeric keypad) and 'ENTER' (numeric keypad) while the title screen is displayed. The bottom of the title screen will become purple. During play use any of the following keys:
'1'--For more energy(player 1)
'2'--For more energy(player 2)
'HELP'------------Skips levels
'Q'--------------Invincibility
When you reach the continue option screen and, if after the word credit, it says 1, start tapping the '1' and '2' keys alternately, all the way through the change disk prompt until both men fall from the sky. This gives you infinite lives.