Right, faint damnation/praise: This is not as bad as the last two installments of the series. Perhaps there is still hope for comedic parody. On the other hand it is still a Scary Movie movie so prepare yourself for tangents that go nowhere and jokes involving toothbrushes and dog rears.
So I was surprised right off the bat in liking Charlie Sheen's little take on paranormal activity. I enjoyed how they turned the amateur video fast forward trope into a Benny Hill take on it. Love the clowns getting under the covers. From there the film coasts a bit before settling into a paranormal activity/moma track that for the most part works. What doesn't work was trying to shoehorn the Planet of the Apes and Black Swan into the mix. That pretty much is like mixing a good mole sauce with pickle juice and stewed prunes. It is not advised.
So for cheap laughs and low expectations you can certainly do worse. Take a look at the "fill in the blank" movie franchise as a prime example.