Episode 1 is good, and really served to pique my interest.
The Divers are given an exciting opening, and Aiko's slice-of-life intro works pretty well at giving us a sense of her character and some of her immediate life struggles. Some genuine mystique is built up around the Matter and its' role in the world, and the pacing works well.
After that, though, I think my final impression of the series gradually turned into something a little above average at best.
There are some solid parts to the series overall. The mechanical designs of the vehicles are pretty good and are well-animated CG, and there was some nice effects work on the synthetic suits and other technological elements. They also picked really fun intro and outro songs, I enjoyed those a lot.
For a while, I watched with the impression that the story was going to turn into something interesting, and say something I hadn't heard on the subject of human-machine coexistence. The setup of the Matter, artificial organisms, and the emphasis on medical technology and life-saving surgeries seemed novel in its' treatment, at least at first. But all the payoffs fell short of my expectations, and the story gradually unfolded into a much sloppier and more generic take on the subject.
There are three big problems with the storytelling in this show.
One is the confused morality it attempts to use throughout when talking about the moral rights (or lack thereof) of synthetic beings, which feels more pedantic and poorly defined the more the story tries to explore it in any depth. This is most clearly seen in Yuuya's character, especially in the latter half of the series, and the main justification for his disregard for the rights of artificial life seems to be the fact that he's a smart cookie scientist so shut up. Conversely, anyone arguing for the intrinsic value of said artificial life exclusively does so through the "but I like them and my feelings are real so they must be real too" empathic argument, which, again, is sloppy and unsatisfying. So it strikes out on both counts, in my opinion. In the end we *mostly* get the lazy light/dark bio/artificial we-cannot-mingle apartheid mentality, which was just a disappointment.
The second is the way the story executes its' attempts at thrilling twists, which often *almost* succeed, but which either rely on narrative ass-pulls, or - in one very important case - confuse things to the point of near contradiction, only to be (mostly?) patched by borderline retroactive storytelling (e.g. Aiko's eyes; you'll know it when you see it). The result is that there is no point where these twists directly build off a past hint or event without introducing outright new information that was previously hidden from the viewer, and impossible to obtain beforehand. The result is that I basically shrug and throw my hands in the air whenever it happens - because how am I supposed to even try to predict a twist that only the writer can see coming? (This is a classic mistake in bad mystery story writing. The reader should *always* be given just enough information to figure out who killed who with what and when, IF they care to put in the effort before reading what the protagonist detective thinks. That's part of the fun. There's no point to this, however, if it turns out that the real killer escapes all detection by everybody until the final act, and only appears at the very end, impossible to predict beforehand. That's not a mystery; that's a joke. Or cell assembler #3.)
The third is the fleshing-out of the technology. Most of the story is grounded in the concept of the "cell assemblers", which are basically synthetic biological cells which mimic their biological counterparts. At first, things seem to tick along pretty well in the story. The most outlandish thing we see is the "Matter", the uncontrolled bio-hazard which coats a good chunk of the local landscape; but it behaves in ways that seem plausible despite its' alien and uncontrolled mystique. However, as the story progresses, things become increasingly murky in terms of how things work or what we can even expect to be possible, and the show dabbles in random telepathy and spontaneous clairvoyance that have NO clear or even attempted explanation other than "synthetic biology did it. somehow.". This means that the stakes and the dramatic tension become increasingly murky as well. And that's half the story right there, really. I think the most blatant example of this is the entire subplot for Isazu and his daughter, especially right near the end. What starts as a tragic bond between father and daughter becomes an increasingly scattered and cluttered mess of a dramatic subplot that really comes out of left field, culminating in some borderline nonsensical biotech megalomania that feels awkward and shoehorned in. (In fact, a lot of the final conflicts in the last four episodes feel awkwardly bolted-on in this way, rather than clear logical extensions of what came before.)
Aside from those glaring issues, the action scenes were decent overall despite an occasional choppy shot, but I will admit that endless scenes of relatively samey Matter attacks did start to get old sooner rather than later. The voice work was decent, no real complaints there. The setting art was a bit on the darker and more unstimulating side, but I think it was serviceable.
One general complaint is that there wasn't much character development after episode 4 or so. Most of the characters don't really grow or change in significant ways, and most of their interactions are either cocky battle chatter or scared yelling, without much depth or insight into who they are or why they live the lives they do (aside from one rather awkwardly blatant scene on an outpost rooftop...). As well, for all the screentime Nanbara gets, I didn't really feel like her character contributed much to the story other than some occasional narrative convenience and a halfhearted take on political intrigue. Her stance on why the matter shouldn't be destroyed, which is practically her defining character trait, is never really clarified or challenged in any depth, and becomes moot to the story except as a means to buy time for other characters later in the story. She could have either been made more relevant, or cut near entirely.
The scenes that aren't mostly banter or battle cries are fine where the story manages to keep itself coherent and on the rails. But Aiko is a mostly passive and reactive protagonist who is literally shuttled through the story from start to end, and this is a serious problem in itself when most of the story is centered around her point of view. Many of the action scenes don't even involve her all that much, other than to show that she still exists and is struggling with the situation. The only active decision(s) she makes after episode 2 is to keep going on this field trip in the first place, but her only real strengths are that she's a nice person and has a high pain tolerance. That's about it.
In short, this show initially seemed to offer something fresh, but ultimately fails to deliver on that impression. If you want a half-decent scifi action show to burn through one afternoon, this is fine for that, but I don't specifically recommend it beyond the first or second episode. Skim through it if you want to see more of the tank and vehicle designs though, they're pretty fun to watch as they scoot around.
Thanks for reading.