Like many, here, I stumbled across this gem in an 8 disk box set called "CULT HORROR CLASSICS" about 8 months ago. Obviously, I wasn't looking for a TIMELESS CLASSIC. I love most bad 70's horror films the same way I love a puppy that's so ugly, it's cute. After watching "THE DEVIL'S NIGHTMARE(the title of my copy)", I watched it again, and then twice more. This wasn't a bad 70's horror film. It was an outstanding piece of independent film making. Don't even bother watching this movie with any intention of comparing it to modern cinema. But, if you like horror movies from way back,you will be pleased.
Many have said that the dubbing and the acting(of the "other" characters) are neck and neck for the worst thing about this movie. I've excused the acting as poor translation from European to American audiences. The dubbing, I blame on the lack of guts needed to put some money into the American release. I even excused that because the film industry still seemed to think that art should be safe, back then. My least favorite thing about this movie was the video re-mastering. In some spots, it bordered on cartoonish.
OK, seven tourists=seven deadly sins get stuck in creepy castle where butler lays the family curse rap on good and thick. The creepy castle and family curse were horror movie staples. But, in cinema, the 7 Deadly Sins were a lot less cliché, in 1971, than they are, now.
For me, the biggest scene stealer in this movie was, despite the bad re-mastering, the cinematography. Lon Chaney(Sr. and Jr.) would have applauded the way their art form was used(with a step from one light, into another) to take you from gazing on Erika Blanc's stunning beauty to the faced that exposed the ugly, inside. In other scenes, she took it to a higher level with facial contortionism that few Hollywood starlets, of the time, would have risked their "PRETTINESS" on.
I'll admit that the first time I watched the infamous girl on girl scene, I enjoyed it on a level that a healthy red blooded American man would be expected to...With guilty delight! By the third viewing, I wouldn't have been surprised to find that, in the film's original quality, this scene bordered on tasteful. Also, this scene is criticized as irrelevant to the story line(if you can put on a better show of two of the deadly sins colliding, stop criticizing and start making movies). The look on Lust's face said a lot after she pleasured Sloth and, when it was her turn, Sloth did her thing...SLOTH. Some SINS made it to a top 7 list for a reason.
As others have stated, one of the film's highlights was the guy that played the Devil. Little(if any) special lighting was needed to take this guy's creepy ugliness all the way back around to an, even, creepier beauty.
I'd like to sum this up by addressing those who accused this movie's American release as "COATTAILING" The Excorcist for two reasons. 1: This movie predated The Excorcist by a couple years, and 2: If "THE DEVIL'S NIGHTMARE" had been a full budget Hollywood production, I have no doubt that I'd be here, now, explaining why an, almost never heard of movie called "THE EXCORCIST" wasn't as bad of a movie as today's critics make it out to be.