The poor and mediocre ratings reviewers have given IO are from viewers who may not have realized what they were getting into. Part of the problem may be with the preview, which focuses on the sci-fi 'escape from an apocalypse to the stars' basis of the movie. People may have come to it looking for a thrilling human vs environment action/romance and instead received a thoughtful interpretation of humanity at the end of its rope. The interactions are complex and yes, sometimes a little off-putting. But give this movie a chance. Relax and enjoy it for what it is: lonely people surviving in a harsh world while exuding their humanity in the same subtle ways all of us do.
It won't be for everyone. But I hope everyone will appreciate that the movie was visually convincing, the acting was strong, the writing and direction were great and the characters, while some will even dislike them, are real and consistent and very much human.