The board titled The Depths is not actually accessible from any of the game's other boards. This board has its own connecting board Nightmare, which contains one of the game's five purple keys, and so the game cannot be completed without cheating.
(Report entered by Dr. Dos, original report by The Green Herring)
But of course,I mainly use MZX. I'd just use the ZZT to MZX converter on this thing,put a 'playershot' marco on all the objects. Put a explode (number) marco on the objects AFTER the 'playershot' marco. Play the game,and just blow everything up.