During play, hold down 'A', 'G', 'E', 'S', and press the left mouse button for infinite everything. Now use the following keys during play (doen't work on the amiga 1200).
'F1-F5'--------Jump to corresponding level
'1-3'--Jump to the corresponding sub-level
'4'----------Jump to the end of level boss
'F6'----------------------------Atari mode