Premise and the trailer were good. That's it. Literally it, but the actors do try with a very repetitive and shallow script. The lighting was apparently done by two different guys who never worked the same day as the other or even spoke or met each other. The soundtrack was lifted from the world's worst seedy nightclub that burnt down and THEN they recovered the music. There are NO jump scares, there are no creepy bits just moments when the music fades out and back in and one of the characters moves a bit slower.
If it was presented as a supernatural thriller then yeah ok, but it's not an out and out horror, and cause it's presented as such you're just left disappointed.