SILKWORM:

        On the options screen, type "SCRAP 28" for infinite lives.  Press
        '0'-'1' on the keypad to select levels.  Use the funciotn keys for
        variable slow motion.

        Version 1- Hold down the HELP key and keep it pressed while pressing
        fire and you'll get infinite lives and can move thru the levels by
        pressing the numeric keys 1 to 0 and the minus key.

        Version 2-If you have the latest version then attempting the above
        will reveal the message: 'Congratulations!, you have found the cheat
        mode...
        unfortunately it has been ZZAPPED!'. If this happens goto the control
        selection and type 'scrap 28' and then start the game. The effect is the
        same as above.