Very sleek looking low-budget Horror with a plot that is so simple it confuses many people. In fact, the ending spells everything out in clear, precise terms. It even has a few lines that are a complete synopsis of what happened and the flashbacks make it as clear as the driven snow. So the reaction of some that it is incomprehensible just does not hold up.
Yes, the telegraphed "surprise" makes the twist a bit unsurprising, and most will see it coming, but that does not take away most of the gimmicky, but good looking scary movie clichés. It is a restrained production with not much makings at its disposal but takes advantage with a smooth editing style and some creepy, stunning minimalist photography.
This one has an efficiency that is borderline with holding, but it does deliver enough to make it satisfying, if nothing new, in the overused "cabin in the woods" is akin to "batten down the hatches" scenario.