This movie is a little bit stupid. But that is one of its best qualities. Acting ain't great. Special effects even worse (OK, they're better than SOME of the actors).
I couldn't get over David Brandon (Caligula in http://www.imdb.com/title/tt0082133/?ref_=nm_flmg_dr_152) playing a priest. He may be a drunk, but still a man of the cloth. I still can't make it through Caligula 2: The Untold Story in one sitting. It is not only kind of mean-spirited, but actually gross.
I got this on X-Rated (German video label, not MPAA) DVD in a fat box (große hartbox) and the box/case is actually a whole lot better than the film. Way better, as a matter of fact. It's called "Ghost House 6" on the box. Pretty sure it's called "Beyond Darkness" in the credits.