http://www.netrover.com/~timt/cheats/c/cybernoidii.html (Amiga Plus Extra No. 5/97, 05/1997)On the title screen, type "NECRONOMICON" for unlimited lives. Pause the game and press 'N' to skip levels.
If you define the keys 'Y', 'G', 'R', 'O' (in that order) you'll get infinites.