I should first thank the director or writer by choosing a group of ONLY(!?) five people troubled with a "cin"! Otherwise we would have to watch, say, ten or more times the same kinds of hallucinations for each of those ten people! Another point that i am thankful to him is that he saves me from burden of being tense and make "myself" terrified...Well, given that i am dumb and have no subconscious and am unable to create images in my mind by myself and build tension for a few seconds by myself, he had to constantly pump up explicitly with those computerized scenes he composed.... Thank you!!!! To me, half of the success of an horror comes from a successfully created perception of presence where the story takes place in... Even the best candidate places for it were wasted by the director in this movie.
A modest suggestion to him: If he really wants his movies to be scary and more effective, he should turn the sound completely off! Very rudimentary (crude, primitive, rookie) way of using sound effects to create terror...
In summary, there is no art nor art-crafting at all in this movie. It would be a total waste of your money. As usual in his movies, casting is terrible as well. Players may not be pro, that is acceptable. But one needs a little bit effort in the script right!? I strictly advice you to save your money by not supporting rubbish...