I bought this movie for $5 at a used CD store, and I kinda regret it. I'll start by saying I'm a huge fan of cheesy horror flicks. They provide a horribly tacky cheap entertainment. This movie entertained for the first half hour, because it was so bad it could be made fun of in an MST3K style manner quite easily. Then it got boring.
The acting is the scariest part of the movie. While great acting is not to be expected, this was laughably bad and, honestly, provided all of the entertainment that was to be had. This is the plus side to the movie. Where the movie really falters in entertaining is the writing, lighting, and the editing.
This movie provides way too many "What the %$@# is going on?" moments. There are many moments, such as the mother having strange fits at dinner, and then that having absolutely no consequence in the movie. Along the lines of dinner, someone in charge decided it was fun to watch people eat refined food for five minutes straight without dialogue every time a meal was served. During the meals and other inappropriate moments, the scene cuts away to pure darkness outside. Then cuts back in. And speaking of darkness outside, one of the funniest parts of the movie is the climate, where apparently it isn't nighttime unless it's raining. And speaking of darkness, a big problem with the movie is that it's so poorly lit you can't see what's going on half the time, which is more of a frustration than anything. In one of the climactic scenes, you can't even tell what you're supposed to be seeing that's so shocking.
And when it comes to climactic scenes, Unhinged contains one of the worst. I've seen people say "Wow, that surprised me, and that's good." I can say that the big reveal did surprise me, because I didn't see it coming. The reason I didn't see it coming is because it made absolutely no sense. I won't ruin it for you, but I will tell you that my friend and I spent a good twenty minutes rewinding to various parts of the movie to find anything that would have validated that at all, and all we found were more things saying that it wasn't possible.
All in all, this movie is actually better when you watch it with the commentary tracks that make fun of it. I love crap horror movies, but this was too much.