The horror genre has its fair share of influences, taken from now relatively dated 80's horror effects, and the slightly more effective 90's slasher horror arena. Those films were influenced by such horror gems as the originals Halloween and The Exorcist. The Exorcist in particular remains at the pinnacle of the "devil" genre, films that revolve around the concept of demon possession. The devil inside holds a few key influences from a few key subgenres of horror, but never really gets any of them right as it swings from one cheesy scare tactic to contrived plot twist after another.
The film follows Isabella, as her intrigue for the supernatural brings her to Rome and to an insane asylum. After her curiosity simply explodes, she collects a rag tag team of priests and goes on an adventure to the depths of boringness to confirm her suspicions that it may have been the act of demon possession that drew her mother to murder three people decades before the film takes place.
This foundation serves as a formidable plot line that begins as an exploration into the psychological realm of the supernatural vs. the natural. The tonal shift of the film brings things to a bombastic lightning pace, where characters you didn't really care about in the first place go through horrific turn of events that seem forced and downright silly.
The "shaky" camera effect is done here to a nauseating level. Shaking at all the wrong times and in all the wrong places, the camera was likely held on the helmet of an intoxicated squirrel. It doesn't help that the action being viewed on screen is as interesting as the day in the life of a squirrel.
The movie isn't particularly frightening, as the shoddily crafted plot towards the second arc never develops enough for the fear to hold any weight. And the thrilling nature of it falls flat, making for a movie that isn't all that thrilling, and isn't all that scary. It becomes a drab mess of washed out grays and cut-out carbon copy characters. Paranormal Activity is similar on the surface alone, and that film succeeds because the "gimmick" and design of the films are substantiated by an intriguing plot. The devil inside meanders for far too long, and tries to convince us later on that the whole thing means something. Paranormal Activity has results and a payoff that makes the unconventional and bizarre construct of the film rewarding. The devil inside ends on a note that is beyond incomprehensible, and arguably insulting to the viewers who were dragged through its only 87 minute duration.
Every influence The devil inside uses, it absolutely demonstrates a total lack to represent it with an even mild amount of success. The poor camera mechanics, the plot that feels like a patchwork quilt worked on by a toddler, and characters as thin as paper and as intelligent as the squirrel holding the camera, The devil inside fails on many fronts. Lamenting horror clichés and circulating awful film construct, the film's ending only proves that it was accidentally marketed as a horror film as opposed to the next Scary Movie.