So maybe I wouldn't have lifted the title from the Horta episode of the original Star Trek. But anyway. Two estranged brothers go camping and hunting in an effort to reconnect after 15 years. Things go badly. What lifts the body of the movie above a standard 'Run through the jungle' horror scenario is the emphasis on the roots of this strained relationship. That and the refusal of the movie to categorically explain what is stalking them and why. It's amazing what a bit of mystery can do for your horror movie -- or at least a refusal to indulge in too much exposition.
The monster, when we see it, is interesting enough. I certainly wouldn't want to meet it when I was camping, which is why I don't go camping. The two main actors do solid work -- the family drama is believably written and believably portrayed by these two. The last five minutes or so elevate the movie from lightly recommended to a full recommendation.