Paranormal Activity is low-budget horror that works rather effectively on suggestion and the way things can go bump in the night.
Director/writer Oren Peli's gritty, naturalistic pulse-pounder set over three weeks in late 2006 in San Diego gets better (like the first Blair Witch Project) as it goes along. Ideally, the midnight screenings have generated much excitement which has brought upon some shrewd studio publicity and tweaking of the final product (shot in a week in Peli's home) probably augmented into the 35 mm format.
Here's a case of mitigating the violence and splatter with the same kind of approach as the hit Cloverfield, but far less lavish, as the meager production with hand-held camerawork indicates. What unfolds is highly atmospheric and carries much apprehension along with it from discovered camcorder footage.
A local twenty-ish couple Micah (Micah Sloat) and Katie (Katie Featherston) have moved in a two-story tract home. Day-trader Micah has bought a device to record unusual happenings that seem to plague the residence.
Besides disruptive noises, there are shadows and motioning in their bedroom at night that impels Katie to retain a psychic (Mark Fredrichs). He admonishes Katie and Micah about a complex paranormal condition existing, and it doesn't help that Katie has had a problem with this sort of thing since childhood. The officious Micah doesn't really help much with his attitude and means to identify this phenomena even by way of the dreaded Ouija board.
Sloat and Featherston, whose Katie gets much more on edge, are very believable together in what becomes more disturbing for them and an audience which is able to sense the tension without the cheap "gotcha" scenes which usually settles into a more crude comfort zone for the genre.
The end result is mindful of the demonic without being dirty-minded, something that folks at the Si-fi Channel could use to ratchet up the quality of some of their programming. Paranormal Activity isn't trying to break the mold of the scary movie, but the execution of the audio/visual from footsteps, walking, lights, and doors of its smallness is used to jolting effect with a climax that's more eerie than over-the-top.
What little musical accompaniment is provided by a computer and the real downtime of the film is in the opening reel. Yet, the technique used to make this Activity fly is just simple ingenuity to relate with much realism of the exercising of malevolent excursions that flicker with delight.