A teenager kills herself after an embarrassing video of her is posted online. Then her ghost comes back to torment her former friends. Unfriended is a pretty basic story, nothing that's going to make you say wow. The difference is in how the film is presented. All the viewer sees is the main character's computer screen. The movie is shown as if we're seeing live feed from her laptop. We watch her move the arrow around and see everything she clicks in real time. In one window she's talking to her friends over Skype. In another, she has a private chat going on with her boyfriend. She has her music playlist in another window. In her web browser, she has Facebook and YouTube open, and she does other web searches over the course of the movie as the plot demands.
And we don't just see what she does, but we see what she almost does. We see every sentence she almost types, then erases and rewords before hitting enter. Because of this, we're privy to her thought process, giving us more insight than movies usually offer. While the characters know a lot more than the audience initially sees, over the course of the movie you find out more of the details that led up to their friend's suicide. Again, none of the revelations are going to blow you away, but the style is so original that it's hard to look away. Despite the relatively simple plot, this is one of those movies where you need to pay attention every minute (sometimes to two things at once) or you might miss something significant.
It's tempting to compare this to "found footage" movies like Blair Witch or Cloverfield. However, found footage movies are inherently less scary to me because, by definition, everything in the movie has already happened. Unfriended, however, is presented in such a way that it feels like it's happening right now... to you. If you let yourself get drawn in, then your TV screen becomes your laptop. The limited view increases your fear, because you feel like something's in the room with you, but you can't make main character turn her head to see.
As much as I liked the concept, I hope this doesn't become a genre like found footage movies did. The uniqueness of this film is what makes it cool, and it's definitely worth seeing once. But in some ways it's more like reading a movie than watching one, and once you're over the novelty of the format, it's not the kind of experience you're likely to sit through twice.
So give this movie a try. And for extra fun, watch it on your laptop.