Plug your Joystick in port 2. Load the game and wait for the title music to start. When this happens, on the high score table the clydes will stop. Waggle your joystick furiously. The clydes should do a dance and turn grey. You now have infinite lives, except on the torture screens.
Pause the game and type "A FINE KETTLE OF FISH". This gives you infinite lives and use of the following keys:
'F1' - STAGE 1.1 | 'F4' - STAGE 2.1'| F7' - STAGE 3.1
'F2' - STAGE 1.2 | 'F5' - STAGE 2.2'| F8' - STAGE 3.2
'F3' - TORTURE 1 | 'F6' - TORTURE 2'| F9' - TORTURE 3
'F10' - Skips to next level | 'C' - Shuts cheat off