Oh, it's fine. Not superscary, but creepy enough to give a few chills. The overall quality is great for a film made for $15K.
The male lead ("Micah") is very unappealing. The audience had more vocal reactions to his stupidity and macho posturing than to any of the eponymous paranormal activity.
Like Blair Witch, it's a cheaply-made movie with a good concept and execution , but with rotten characters that detract from the experience.