I watched this movie twice, once late at night after my kids were asleep because I knew it might be a bit scary. That first time I was a little bit disappointed and bored, but wasn't really 100% paying attention because I was tired and using the computer while watching.
OK, so I watched it again the next day because I didn't really see the ending the first time, and I knew it wasn't even close enough to being scary to bother my kids. And the second time, doing nothing but watching the movie and understanding what was going on, I found the movie to be a lot better than I thought the first time.
You start out thinking it's a "mockumentary" like Blair Witch and a little monotone, but with a bunch of classic jokes that jab fun at the Horror genre. But that's just the movie's way of completely dropping your guard and fooling you into thinking you know what's going to happen, and it's particularly effective with long-time horror fans like me.
Then the mockumentary melts away into a horror movie where you *think* you know exactly what's going to happen even though every time you think you know what's going to happen you're wrong, then every time you guess and you're still wrong.
Sure, there are some cliché horror movie parts that are predictable including the very end of the movie during the credits, but this IS a horror movie ABOUT a generic slasher horror movie story, like an examination from the other side, so where else would it lead? There are key turning points in the story where you realize what's going on and sudden realizations of how the characters really fit into this story.
So, it ends up being a standard little slasher movie like the classics (Friday the 13th, Halloween, Nightmare on Elm Street), but it's surprising and incredibly smart when you think about how the movie got you to that point from the beginning.