1). The soundtrack was stolen from Friday the 13th who stole it from Psycho. This is the weakest version of the three.
2). The demonic, murderous children are from a number of previous horror films including The Bad Seed and The Omen. Again, this is the weakest of the three and this theme would go on to greatness three years later with Children of the Corn. [One of my faves from the 1980's]
3). Clueless parents appear in films too numerous to mention. They seem especially clueless here.
4). Sex = death has been done as well. Many "sluts" have been the victims of heinous crimes in slasher flicks such as Black Christmas and Friday the 13th. Here, it's a dull and lifeless retread.
5) All the murders are relatively bloodless. This is not a drawback in the hands of a director like Alfred Hitchcock but here, in Ed Hunt's hands, the kills are a total yawn-fest.
Holy cow, skip this crap-fest altogether. It's not even so bad that it's funny. It's just plain bad.
For more info check out the film's entry in IMDB.