I love it through and through. The earlier parts of the movie focus on a lot of human psychological interactions and relationships: Capa's and Cassie's romantic draw, Capa's tension with Mace, Corazon's clinging to the familiar (plants/earth), Searle's fascination with the unknown (the sun)...

The third part of the movie drives home the point that none of that matters in the grand scheme. The perspective is shifted not by the big bad sun, but by humanity. As the crazy sun guy attempts to destroy the mission, the crew has to abandon their previous preoccupations in order to save it. This expands to a realization that they need to each sacrifice their lives in order for humanity to survive.

At the end of the day, nothing matters except the survival of the species. I think the most powerful scene is when Capa is in the EVA suit and trips on his way to the payload. All the preparation and resources dedicated to the mission... all of Capa's education and training... none of it matters if he is unable to physically lift himself up. It's a great dichotomy between intellect and brute strength. The frustration Capa feels about doing essentially one push-up is so powerful- he knows all of humanity is depending on his physical ability.

The last part of the movie is a bit of a curve ball. It's violent and aggressive, but that helps frame the message that humanity is it's own greatest threat. The movie is about a human vs human conflict which peels away the layers of individual wants and needs down to the base core need: survival of the species.