I don't know what to say about this one. It's an original approach which is great, but I felt that the execution didn't really work that well. I think the first plot twist should have been the only one and should have happened much later, like...in the last scene.
Even if the production values and the acting are positive things to mention, I don't think the film did something particularly well (except the existence of the first plot twist). The first act was a bit lame and not that exciting (ok, the build-up on these films is always very similar but this wasn't one of the most exciting), then the suspense and slasher elements of the 2nd act run for no more than 10/15 minutes (the best part of the film) and after that we have the 2nd plot twist that doesn't need to exist and it's not that interesting ending on a low note.