I saw this last weekend. It's apparently based on a Polish graphic novel, so the story arc felt exotic compared to a lot of U.S. films, even science fiction (it was made in Europe as well I think, looking at the credits).

It was a good film but I still feel like there were some elements of the premise that remained unexplained. Or maybe I'm dense. I'm afraid to say too much about it for fear of spoiling, but here's my understanding of it:

It takes place on Earth, post-cataclysm which was caused by an alien race destroying the moon. Now they're stealing all the Earth's water to use for fusion energy, and 2 humans remain there to complete the evacuation of the planet of enemies through the use of drones. At least that's what we're supposed to think.

If anyone has a more accurate take on it I'd like to hear it!