Let me give you the tip, not to expect too much of the film. I had a chance to watch it at the Fantasy Filmfest Nights here a couple of weeks ago and was rather disappointed for several reasons, which may not apply for all, because silly acting and tedious long plot parts may be part of such films and not as annoying for others as they were for me
It would surely have helped to have some sympathy with the characters, but it just was impossible for me... The nature pictures are absolutely great (as the trailer also shows) and the tribe is fantastically strange but it also plays a part in the things that went wrong for me. And normally logic is put aside for films, but as I try to take cannibal films as real as possible, reality check kicked in and I noticed that it is rather silly to have such a hidden tribe dressed - this shouted "MPAA, please accept this" to me and that should not happen in a cannibal film and felt almost cowardly to me. The gore moments are not as many as some may think, they are solid, but since they are mostly not really new, they did not work well for me...
And the ending was complete bullshit for me, but that may go to far into spoiler regions...
I am not saying it is a bad film, but if you expect a taboo-breaking big shocker, you may come out as disappointed as I did. But maybe I am alone in this, other people liked it, oh well...