I think my rating may be a bit skewed from this being my first rating, but wow!
I due my due diligence to try to be understanding of specifically invisible and mental disabilities, so this kind of take is a soft spot for me. I love the use of music, sound effects, and the restricted space. It reminds me of the original Saw movie, which was made by a group of film graduates who rented out a single room to make their movie in, and told a story of being trapped there.