Pull down on the joystick then press 'P' to pause the game while still in the crouched position. Next press and hold 'CTRL' and press 'HELP'. This will give you infinite lives.
Use the following keys:
'F1-F10'----------------------Level select
'1-5'--------------------More level select
'RETURN'------------------Shake the ground
'S'----------------------------Plays sound
'UP CURSOR KEY'--------------Sound minus 1
'DOWN CURSOR KEY'-------------Sound plus 1
'D'------------------------------------Die
'HELP'--Toggle one and two button joystick
'M'---------------------------Toggle sound
'SPACE'--------------------Not really sure
'CTRL'-----------------------Invincibility
With Invincibility you can move the guy anywhere using the mouse. When you have him in the desired position press 'CTRL' again to release him. The right mouse button also acts as a pause.