I highly enjoyed this film because of it's good cinematography, tension and suspense however the majority of the reviewers here haven't. At first I was turned off by the low IMDb rating, but I watched the film because of it's interesting "home-invasion" plot line anyway and ended up enjoying myself and questioning the cause for the low rating. So I went back onto IMDb to read some of the reviews to see why people didn't like it and the main complaints seem to be that the movie was "confusing" and that "it made no sense," with also the classic "pile of crap" compliments for it being thrown in. Personally some of the greatest movies are so good simply because there is no explanation for them and if you especially go looking through the artsy circuit you find a lot of gems that are good because they don't solve themselves. Think Under The Skin, Dune and Hour Of The Wolf...although Mercy doesn't completely figure itself into a bizarre weirdness of those type of films they are great examples of movies that are good because they have no answers. Under The Skin never explains why Laura is abducting people into her body, Dune never explains what the hell is happening and Hour Of The Wolf leaves the insanity of the characters to our own imagination. This film is a home-invasion movie that achieves the technique of not solving the questions and instead fulfilling us with a good, interesting and satisfying experience that also expects us to do some work as well to solve the questions ourselves. Overall if this sounds good to you give this a watch and you will be pleasantly surprised.