Solid acting, a quite original concept, and a well woven tapestry of a... shall we say, alternative culture, make this into quite a strong movie. I found myself invested in the main character enough to care about the outcome, and intrigued enough in the "elder power" around which the community revolves to want to know more about it. I will say it is not a conventional horror movie, so those who hope to get jump scares and loads of blood are better off looking elsewhere, but if you want a thoughtful little film that still has an element of supernatural, this might be a good one for you. Definitely worth watching, and all the better considering what an expanse of recent garbage this little gem shines out on.
Addendum: I saw some criticisms of this movie and they mostly seemed to center around the idea that it left too many questions unanswered, that it didn't have enough of a story, or that it didn't wrap up to a particular viewers satisfaction. I could not disagree more. The premise is that there is an entity whose older than man whose thinking is unfathomable. To answer the nature of such a creature in your narrative would destroy that property of it... wouldn't it? Personally, I like the unfathomable aspect of it. I like wondering about it but never being given an answer. As to the ending and the lack of a story, without giving anything away, well, a group such as this would have developed a kind of relationship with the entity which would have become very entrenched over time. This tale is a slice of time... not a closed end, and I think the ending we are presented with is the perfect one for the, shall we say, nature of the beast. It is precisely these kinds of things that make the story a bit more innovative and not just another Hollywood style tale designed to satisfy the person who prefers things to be more predigested.