I found this movie to be entertaining with interesting dynamics amongst the initial group of survivors. As noted in the trailer (no spoilers here), the survivors are pitted against a pack of wolves (or similar species). The only disappointment to me is that the wolves did not seem real. The animators should have done better.
Who lives and who dies? How many times have we seen this used? I think of The Poseidon Adventure or similar movies where we asked that same question.
I will tell you that the usher told us to watch the short clip at the end of the credits which might provide a clue.
Also, my experience was marred by some intellectually challenged individuals sitting in front of me. They didn't understand the movie and wanted a definite conclusion on some points and ran out of the theater yelling for a refund.
All in all, not a movie for the faint of heart, but a good watch overall.