I didn't find this to be nearly as bad as others have, but it isn't very good either, and certainly needn't be sought out to be watched.
It starts well. Somewhere in America, a killer is being walked down a very white hallway, down a red carpet, to an execution chamber. This is intercut with the crime scenes of the various women he has killed. This prologue was nicely done, I thought. The killer makes threats to return to kill more women, to kill these people's children, and he claims to be the angel of darkness and speaks in a demonic voice.
Nineteen years later, inexplicably somewhere in Europe, a group of young women are staying overnight at a girl's school doing a "stay awake" to raise funds. The killer shows up, first apparently as a poltergeist. We see shots from his POV, drifting into the school, through the hallways, as chairs move around, a picture falls from a wall, etc. This is intercut with the women doing aerobics in the gym. This scene goes on for some time. Some young men show up at the school to try to scare the women, and to hook up with them.
It's quite a while before the killer strikes, about fifty minutes, I think. He appears both as a sort of cross between Gozilla and a giant rat with glowing red eyes and a whip-like tongue, and as himself with glowing red eyes. As the former, it's pretty silly-looking; as the latter, he's fairly creepy looking.
There were some scenes I liked. One I recall: the women are scared by a gorilla mask which is thrown in front of them. They laugh at their fears, but when one of them picks it up she finds it to be heavier than it should be....
The voices do seem to be strangely dubbed. As far as I could tell, the actresses were speaking English, but at least a few of the voices don't seem like they would belong to the actresses. The young women's characters aren't well differentiated from each other, nor are the young men. Frankly, it's hard to tell most of them apart even visually.