I've watched it several times, one of my favorites.
I feel like is a very underrated movie and I can't talk much about it cause at the time I haven't met someone that has watched it, neither did the people I recomended it to.
My favorite part is when the main character finally discovers what the Aratare are made of and explains it to the others, mostly the part where when he's finishing, and some start to ask things as if trying to find a flaw in the mc conclusion and plan.
The Aratare weren't just a bunch of material beings with the forms of real people, but the actual people, which means they where also kinda controled by their actual brain and so that means they could have had some humanity but didn't show any, they only attacked and killed anything and everyone, and is unexplainable too, why where they so careless? Did they lose their memories or humanity at some point in that process? Or maybe the scientists stole all of those things from them? There was one Aratare trapped in one container that looked sad, even as if crying, or something similar if they even were able to cry, that's a drop of humanity right there and yet it still just focused on do what all the others did, run, jump and kill people as if nothing. And the limit of production of the factory, I know they might have had many people to create the Aratare but surely at some point the factory woudn't have been able to continue since it was one person per Aratare, and how they transported the Aratare to the containers, cause there were way more Aratare than the number of broken containers at Masarov, which means that probably somehow after creating one Spectral it was sent automatically to one of those empty containers and easily got out, while the others just stayed there, still that's not explained or shown so that how I would explain it, my theory.
I also found some things that I know might be just little details but I would have loved in the movie and would have made me completly ignore all of the other things and is that the Aratare are visible sometimes even if they're not being pointed with those reflectors. I would have liked a little more of detail there, making it be more realistic, but if I ignore my perfecionism, that doesn't bothers me.
Really good movie, loved the mc's personality btw, not the same but almost reminded me of Doctor House.
Oh! And the sound the Aratare made, also loved it.