Practical effects and dreadful atmosphere are admirable, but the story is so thin that it could be practically used for one single episode of "Twilight Zone". Pacing is slow and most of the running time is dedicated to elderly people walking and talking. So, besides few chilling shots, there is not much to offer for a horror film that drags too much, even though it runs under 90 minutes.
Haunted by the nightmare visions of many masters, and indebted to a certain silent film brilliance harking back to Murnau (there's some shockingly moody cuts, beautifully uncanny silhouettes and melodiously disturbing slow-motion here), but creates a mood all of its own, desperately infused by that maxim so dear to the horror genre: remember that you shall die. And remember that you do not have control of your life.
Thoughtfully constructed, well-paced, and suspenseful. A canny red herring leverages key audience assumptions about subgenre and pairs them with a traditional plot twist. Kerin and Jarratt are attractive, naturalistic, and relatable leads, so the stakes seem high when their lives are threatened. It's easy to wink at the film's shortcomings, including an outrageous (if fun) finale, when so thoroughly entertained.