Perhaps the most terrifying part of the movie was how convincingly real it was. The acting and filming style in this movie were perfect - to the point where it genuinely felt like I was watching real-life footage. The best part of the movie was the build up of suspense and dread. It was done so well it became a masterful manipulation of the audience's emotions and reactions. After the movie, I was literally shivering from being so tense for a whole hour and and a half. This is probably one of the best movies I have ever seen. Will I watch it again? No way. Not because it wasn't good, but because I don't want to sit through such a terrifying movie again.