Exit 8

This is the movie you should watch instead of Backrooms. Just kidding, I haven't seen Backrooms (yet) so I can't judge, but wow its hard to top this one. Exit 8 is about a guy with asthma trying to exit a subway station and he finds out that he can't escape, stumbling upon the same exact corridor even as he keeps moving forward. The only way he can advance (he starts at exit 1 and the end is exit 8) is by finding something off about the current corridor. So he walks and walks, checking off every little detail of the white tiled subway corridor until he finds something wrong, at which point he is to turn around and "advance" through the never ending station. This movie is phenomenal in the way it advances the story while staying in the exact same place. Every time he "resets" and comes back to the first level in despair, you are anxious to see what is the next glitch in the station he will find. With each glitch you get more and more details about some of the strange things he sees and the tension is real. Awesome movie