Play the original in your browser: http://bbcmicro.co.uk/game.php?id=2506
The project's official page is here: https://bitshifters.github.io/posts/prods/bs-ghouls-revenge.html
Instructions can be found here: Ghouls: Revenge instructions
The GitHub repo includes full source code, so you can build and modify the game yourself. See Ghouls: Revenge build instructions