It's trying too hard to be clever. I wanted to see more of the world itself but thr characters are awful. Nothing makes any sense.
The movie actually retcons itself at the end by implying that Portman's character was actually the alien all along, which means that the entire story could be completely fake. I sense they're going for the same kind of uncertainty you get at the end of Total Recall but the difference is that Total Recall has fantastic world building and a highly structured plot, so that it is set up in such a way that you can't know for sure what was real and what wasn't... but either way you get an ending. It was either real and he saved Mars or it wasn't and he's now a vegetable. But in this movie... there's no ending. If it turns out the alien was telling a fake story the entire time then the whole viewing experience is pointless because we are left with absolutely nothing. It's like a wild fever dream.
Pretty visuals, although the plants look painfully fake. World mechanics are extremely inconsistent. Throughout most of the film it comes across as more of an infection that forces evolution. A mindless substance that spreads the Last of Us style and wreaks havoc. But suddenly at the end it's more like a symbiotic consciousness that can possess people and take their physical form. Every character dies in such a drastically different way that it's extremely unclear how the alien actually works or what "powers" it has. I'd of preferred this movie if it were more of a Stalker type product where actual trained professionals are operating in the Shimmer. You could use the same aesthetics and monsters but without the strange, overly artistic and ultimately pointless ending. Like send in a bigger crew with serious equipment, have a large scale operation, get some guns around the border pointed at that thing 24 hours round the clock and plan a proper operation because the girls in there made the most amateur mistakes sleeping with the doors open, not taking night watches, spending so much time chatting shit, dropping their bags constantly on the floor, letting go of their weapons, not using ANY form of PPE before handling alien lifeforms. No back up team, no way of navigation (did they only have one map?), they weren't putting up guidewires or any form of trail to go back, they had no flares, no escape plan, no night visions honestly it just baffles me. They know that this is a suicide mission and yet when they start dying off somehow this surprises them.
But remember, none of this probably even happened because the main character is actually the alien all along so you wasted your entire time watching the movie because you'll have no idea what actually happened and that's that.