Massive waste of time. Extremely repetitive scenery, feux-enlightenment about society, stupid/forgettable characters, and terrible sound design. They really want you to hear every damn chewing sound in this really unsanitary concrete box.
If any of you are told by your friends to watch this movie because it "challenges thought" or has a "good message," don't watch it. They're probably morons or pranking you.
There REALLY is nothing thought provoking about this movie, there is no deep message that will make the average person walk away with an alternate perspective. And sadly, this movie tries really hard to just do that. There's nothing suspenseful, as mentioned in the other comments, because the characters are boring and extremely dry. It's just a weird, awkward movie made by people who felt like putting out a message of what they think is a problem in society. Other than that, honestly annoying - dialogues between characters try to stimulate more thought, but honestly, it's nothing new or different and really just wasted more time.