Just finished seeing this. It's not a great movie, and the "twists" have all been done before in better movies. It's reminiscent of
Moon,
Planet of the Apes,
Wall-E, and there's even hints of
The Matrixin there.
And of course, they get the technical shit wrong. The whole purpose of the "aliens" coming to Earth is to drain the oceans so they can refuel their ship. The thing is, there's more water floating around our solar system than there is in all the oceans on Earth times a million. It's easier to get at, and the aliens wouldn't have to come so far into our suns gravity well to fetch it. In fact, they wouldn't even have to come inside the orbit of Pluto since there are moon-sized bodies of water-ice just floating around out there.
The biggest mistake happens when our hero enters the big bad alien mothership in orbit of Earth. See, it turns out that the aliens aren't aliens (plural), it's an alien AI. And this alien AI has tons of drones for killing stuff, but no drones to actually do work. So it has to find planets that are already inhabited in order to clone and enslave them to do it's dirty work. You know, instead of having its own worker drones...
So what happens if it finds a planet with lots of water but no sentient life? What if the dominant form of life is fucking jellyfish?