Have you seen 'Paranormal Activity 3?' How do you think it stands up to the rest of the series? Leave your thoughts and opinions after the jump.

One of the final promotional trailers for "Paranormal Activity 3" asserted proudly that the last 15 minutes of the movie would "mess up your life." That is a like clarion call to modern horror movie filmgoers.

As with thrill-ride aficionados, what fills the seats on opening day is the promise of the enormous collective shriek, of a build-up and payoff so visceral and ecstatically frightening that the adrenaline and fear keep you up all through the night.

This is not necessarily to promise gore and viscera enough to put you off ground beef for a week but a true psychological jolt. That physical shock of horror is precisely what the series predicated on a haunting by a malevolent, invisible force promises. For those not familiar with the series, the third installment of 'Paranormal Activity' is not the place to start. This is a movie for followers, for horror's disciples.

For these movie fans, the first two-thirds of "Paranormal Activity 3" should not disappoint. It's standard "Paranormal Activity" fare, and if you can at all still be scared by your own imagination you'll find yourself sinking into the back of your chair every time a title declaring the night since the "happenings" started appears on the screen.

The series still operates in the same way, though the new entry is a bit flashier. Video cameras watch over sleeping family members as frightening occurrences start to build around the house. This "Paranormal Activity" uses a new conceit in the form of a camera mounted on the base of an oscillating fan that has you fearfully eyeing the edges of the screen, dreading what's happening while the camera lens is away. Like with all "Paranormal Activity" movies, it's the horror of empty space that really gets you, the suspense of the potential that makes the actual scare all the more thrilling.

That said, it's not as taut or consistent as the first movie, in which the scares were steady and relentless, escalating without release. In "Paranormal Activity 3," the tension is broken by the comic relief of new character Randy, and there's a lot of fairly uneventful exposition (often just rewatching the scene we just saw but this time on a grainy 80s monitor) in between. In the first movie, the mounting domestic squabbling mirrored the haunting and made even the day periods unbearable. Now the ghostly disturbances are more varied and the daytime is more a chance to recuperate than we were ever offered in "Paranormal Activity" number one.

Then the movie changes gears in its last third, departing from formula to dip into more of that backstory that it had been teasing since the series' second entry. This divergence takes on a significantly different horror movie tone that scares less and rushes by quickly. It speeds to a finale that is both startlingly anti-climatic and abrupt. It opts not so much to finish the haunting and the story butto go out with a bombastic showing of the demon's fully-realized powers. It's purposefully elliptical to ensure the perpetuation of the franchise, as if a $50 million dollar opening weekend to the $5 million film were not encouragement enough.

It's the strongest movie opening this year since the last "Harry Potter" movie, and it owes much to the effectiveness of its trailers that show a lot of footage that doesn't end up appearing in the film. Given the fact that the movie's finale feels weak and the scares throughout are sparse and uneven, it feels like the movie got pared down too far in post-production, like the advertisers saw a better "Paranormal Activity 3" than we did.

Without giving away any spoilers, the movie could have used more of the jolts and disturbances the that trailers tease. Because the franchise operates on the fright of the inevitable but the unknown, I have a nagging suspicion that it would be substantially less scary the second time through, a movie re-viewing that the first entry of the series definitely still keeps its teeth in. Have a look for yourself.

Ryan Levin is a University of Michigan Screen Arts and Cultures graduate and a film and comedy blogger. He currently moonlights as a waiter and bartender at the Ann Arbor Comedy Showcase.