Theoretically, it's interesting. I like the worldbuilding, the darkness and the ideas. It's serious SF. Unfortunately, though, it's making some unsympathetic decisions and I can easily imagine a lot of viewers turning it off because they'd stopped caring.
The world's being swept by a pandemic called Randolph Syndrome, although this gets surprisingly little focus here. (There's also, though, a manga called Deep Insanity: Nirvana and a mobile and PC game called Deep Insanity: Asylum. Apparently, half a billion people are in a coma and there's also been a World War Three. This is the sixth mass extinction in Earth's history.) Anyway, there's a subterranean world called Asylum in Antarctica, where people called Sleepers fight abominations and possibly, perhaps look for a cure for the plague. This is extremely dangerous and Sleepers get killed all the time, but that's normal and no one minds.
To summarise in a spoiler-free manner, our Sleeper heroes get highly questionable orders by commanders who never answer your questions. Frankly, Commander Vera Rustamova struck me as incompetent. She's good in a fight, yes, but her man-management skills are zero. Not just "poor". She has none at all. If she'd even tried to explain her orders, Shigure might have made a different choice in ep.6 (for instance). Meanwhile, the Sleepers have to decide whether to follow opaque, possibly evil orders and don't really give the matter significant thought. Eventually, the show goes into SF territory that's theoretically interesting, but in practice a bit dull and inviting you to pick at its logic holes.
To discuss all this properly, I'll need SPOILERS.
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There's a little girl (Elsie) somewhere in the Asylum and Commander Rustamova wants her assassinated. Our hero (Shigure) has even met her. She seemed nice. Nonetheless, it's a Sleeper's job to obey orders, so off they go to shoot Elsie. No one ever questions the morality of this. No one ever suggests that shooting children might be wrong. Every so often, they'll wonder what to do, but then reach a conclusion of "I'm a good soldier and I'll follow orders." At one point, Shigure asks Rustamova why she wants Elsie dead. Rustamova refuses to answer and Shigure seems to realise that the question wasn't actually important anyway.
What? I mean, what?
This is clearly deliberate. We're meant to be unsettled by this. Ultimately, though, the show undercuts its own darkness with a big cheat at the end. Our heroes had been trying to kill a little girl who seems nice, but there's another little girl who's extremely dangerous, is working for the enemy and shoots people. Leaving her alive is a risk, especially in a combat situation. In ep.12, our heroes are in a combat situation and have a chance to shoot her in the head... but they don't. They take her alive and tie her up. "Piss off" was my reaction. Either these are heroes who'd shoot children or they're not. (The episode tries to justify this by having our heroes try to negotiate an exchange with her, but the baddies laugh this off and a few seconds later it's forgotten.)
Then, in addition, we have time-looping in the last few episodes. This is intriguing, but it also makes the situation less urgent. If you die, you'll come back. Big deal. There's also a revelation that X is really a future version of Y, which is theoretically interesting but makes a nonsense of the character's thought processes. By definition, X must have lived through these current events and survived them as Y, so all she needed to do was remember her own history and do that. She didn't. She kept trying to do something impossible and suicidal that would (at best) trip a time paradox and send her back to the start of an idiocy loop.
There's also someone with a really annoying speech pattern in ep.8.
There are definitely things I like here. The character relationships in the later episodes are quite good, e.g. the barbecue comedy in ep.9. I also like the show's tone. It's bleak, dark and taking itself deadly seriously. Ultimately, though, we're watching drab people who come across as both a bit evil and incompetent. Events make a mockery of their decisions. This wasn't a popular show, as far as I can see, and I'm not remotely surprised.
The moral of this story: "if ordered to assassinate a child, the heroic thing to do is not to question your orders, but obey!"