Very impressive effort.
Great cinematography, camera work and aesthetic. The concept was pretty interesting. The acting was decent.
The only real issues are the handful of naff jump scare attempts and the run time. It's 1hr51mins and could have done with a bit of tightening up. Trim 15 or so minutes from it and remove the silly jumpscare attempts and this would have been stellar.
The fact that Sean Ellis was the director, writer and cinematographer was impressive. Talented individual.
A must watch for Horror fans.