The Demon may possess one of the worst story lines, the worst character development, and the worst filming techniques that I have ever seen. It was incredibly spotty and left so many holes like it was a slice of Swiss cheese. At the same time, there is something appealing to this film that makes it worth the watch. While someone who's looking for a film that thoroughly follows the rules is going to declare this to be one of the worst on the market, there should be plenty of people that simply forgive Percival Rubens and the direction he took the film as the director. Having a low budget like that of a pauper would be the only thing that excusable for the quality of the film in general.
The monster in the film is a serial killer that is the title "demon" in the film. He has a razor claw, a mask, and is large and monstrous, like he is a human King Kong. His first victim is Emily (played by Ashleigh Sendin in the brief amount of time she appears), the daughter of the Parkers (played by Peter J. Elliot and Moira Winslow) who summon a retired, psychic marine named Col. Bill Carson, played by Cameron Mitchell, who is probably the most notable star Rubens could get on board. Mitchell does a fine job portraying Col. Carson, as he walks into the room and senses through Emily's items in order to see images of what may have happened to her. The Parkers are like any set of parents whose daughter has been kidnapped, most concerned about whether or not she is alive.
While the beginning of the film provides the notion that the Parkers are the target characters, this notion would be misleading. We should really be focused at Mary (played by Jennifer Holmes), who is a preschool teacher who sees this "demon" pop up outside of the building, but disappear just as quick, every so often during the day. She lives with her friend, Jo (played by Zoli Marki), who is quite the carefree brunette who is starting to date Dean Turner (played by Craig Gardner). Dean is a rich, spoiled, in many cases arrogant individual who likes to pretend to take pictures in order to encourage Jo to shed some clothing. When we see him locking the door and pause, an assumption arises that he is the demon that's killing people one by one. The rubber mask only increases such an assumption.
The demon pops up on plenty of occasions. After Emily, he hops into a car with an outgoing driver that hitches him a ride, he also comes across a few others in which he kills before suffocating them by placing their heads in a plastic bag and tying it. We have no idea exactly who the demon is, for his face is only shown at a quick glimpse.
Mary, who sees the images of the demon, is the one that is given the fate of bringing down the demon, because Mr. Parker tries to confront him using the brilliant sketches that Col. Carson creates through his psychic ability, leading him to the house but is unable to take the demon down. Col. Carson tries to console Mrs. Parker, but loses his life in the process, ending his ability to do anything to solve the problem. That takes them completely out of the picture, but leaves Mary & Bobby and Jo & Dean. Ultimately, it's just Mary that is locked in her house and has to outdo the demon in some way, shape, or form.
There is absolutely no plot structure in this film. There is no explanation about the demon, who he is, what he does, and why he does it. He just terrorizes a town and kills people that cross his path. The Parkers are a poorly structured family and things are just cut off to the point that there is no explanation whatsoever, especially the way it ends. At the same time, there is that certain element that allows you to care about specific characters (primarily Mary and Jo) and want to see the demon be brought down. Mary is the one character that has the wits and the physical ability to resist the demon, knowing that she has to use her head and not her hands to bring this monster down, because he's just too strong to be brought down on a one-on-one fight.
The horror fanatic will see nothing wrong with this film, especially if they can care less about plot and care most about being horrified. This film is rated R, primarily due to violence and nudity. There are quite a few scenes with upper nudity and there is also some complete nudity to go with it. I'm not one to complain about this, but that doesn't mean you should be taking little ones to see this film.
A billboard for The Amityville Horror makes an appearance during a scene that's showing the nightlife of a town. There also happens to be a place calls "Boobs Disco" where they play "Funky Town" by Lipps Inc., leading me to question the year the film was released, because "Funky Town" came out in 1980 and I would find it hard to believe that a hot song would be used in a low-budget film like this. It was filmed in South Africa (explaining the driver driving on what is the passenger side in America), but it states different years of release. In America, the release happens to be in 1981. A few tidbits that add to the confusion, but this is just me.
The Demon suits its purpose and does nothing more. I would say that the horror-goer is the only individual that will enjoy this film and be entertained. If foodies could eat and enjoy American cheese and Velveeta and call it "cheese," then horror fanatics could watch this and call it "horror." I found this film to be quite entertaining, but that's as nice as I can be, because it had plenty of faults and left me with plenty of questions. The ending could be the exception, because cliffhangers can build tension in a piece. It has since become public domain, adding to its overall quality, but it could still make for an entertaining horror night.