This show is hard to talk about, because it's a sad story. It's the story of how a promising show can be undermined by an unnecessary adherence to convention. Oh, you thought I was talking about the plot of the show itself?
Allow me to put this into perspective. The Japanese light novel has a fair bit of history now, but allow me to be glib and say that they're a modern sort of pulp fiction. Pulp fiction was a type of media engineered for popular entertainment. It was printed in periodicals on cheap paper (the pulp in pulp fiction). If you were to simplify all fiction into either, "genre fiction," or "serious literature," pulp fiction was all the way on the genre end of the scale. The medium gave rise to some storytelling trends of its own, such as the two-fisted tale. Much of the same can be said about the modern Japanese light novel.
This show wears its light novel trappings on its sleeve. This is apparent from the title alone. It's entirely too long to remember, much less recite, inviting people to invent some marketing-friendly fan nickname. It's set in another world. There is exactly one guy in the main cast. There are some vaguely-defined superpowers involved. The main girl has long hair, at least past the mid-point of the back. There are probably many more examples I could have listed here.
Very little of this is obvious from the start of the show. The first episode was so enjoyable and well-crafted that I paid these sorts of things no mind. In retrospect, there were a few fears which had gathered, though I hadn't put words to them yet. A good show draws you into its world, and lacks annoying distractions. You aren't likely to think about this sort of thing during a good show. However, the rest of the show wasn't up to the standard that first episode had set. By the end of the fourth episode, I had put words to the fears, and found justification for them.
The first concerns the plot. This is one thing which isn't necessarily light-novel-ish, and seems to be more like one of Key/Visual Arts' so-called "utsuge," or "crying games." I disliked these sorts of stories for being emotionally manipulative. They would unabashedly use cheap tricks to get you to feel sad. Thus, the fear, "Will they have these girls dying off one by one for cheap tears?" Now, a little tragedy isn't a bad thing. However, the end of episode four was troubling. Right after stirring the depths of main guy's trauma, main girl did a stupid anime rom-com thing and broke the tension. Thus, at this point, I don't trust this show to handle tragedy appropriately.
That isn't even the only problem I have with the plot. Main guy's backstory is presented a bit out of order such that it induces a bit of a plot hole. It made it clear that he was there to see the destruction of the surface world, yet also that this occurred about 200 years ago, long enough that his native language has become a dead language. How this is possible wasn't made clear until later. Even though we can accept the explanation via willing suspension of disbelief, since it's arguably necessary for the story to exist, there remains the question of why it was presented in this haphazard way.
The setting has a bit of a similar issue, though it's more of a mixed bag. The airborne cities are beautiful, and I'm happy to set aside questions of how such things exist to admire them. The fact that they're filled with the so-called, "featured," humans with animal traits, or maybe sentient human-like animals, is also interesting. This actually creates a bit of a problem, since the story only deals with these things superficially. I want to see more of the world outside the orphanage-prison, but the plot isn't really interested in these things. The plot really only cares about the fairy-girls. The "featured" seem to only exist to isolate them, and to not-so-subtly encourage the viewer to empathize with them. You see, this is a harem show.
In fact, it's a themed harem. The theme? Lolis. Yes, inner cynic, the orphanage-prison really is a lolicon paradise. It was a totally gratuitous fanservice shot, of one of the younger girls, that verified this for me. The presentation is a bit misleading in this (Black Bullet was a lot more transparent). It's even possible this wasn't the author's intent, but it's what we got anyway. Main girl is supposedly 15, which should be outside the lolicon range, but she's drawn like the object of a hebephile's wet dream anyway. In some other show, I might have written this off as her being the flat one, but it's hard to interpret her any other way in this context. There is a full-grown woman around, but she's treated like a joke by the narrative and as a nuisance by the main guy. It's normal for a harem show to feature a character, the "harem nanny," whose purpose is to manage the harem; this is literally her job. She is a walking TV tropes entry.
Several of the other characters are easily dismissed in this way. Nephren is the nigh-emotionless girl. Ithea is the gadfly. Chtholly, a.k.a. main girl, is the tsundere. Up until the end of episode four, I had a better opinion of her. After that, it's clear that being a tsundere is her defining character trait. It would be easy to declare main guy, a.k.a. Willem, to be the typical slightly moody light novel protagonist. For once, this seems to be a bit unfair. His broodiness stems from understandable guilt and unresolved grief, and he doesn't seem to project the typical too-cool-to-care nonsense that generally goes with the archetype. Whether he's as overpowered as the typical escapist protagonist remains to be seen, but the fact that he's been defeated at least once, and even shown as mostly helpless in the scope of the narrative, makes it hard to compare him to the likes of Tatsuya Shiba.
All in all, this show could have been something good. This isn't mere speculation, as the first episode stands as testament to this potential. It has aspects I like without reservation, such as the scenery porn and the soundtrack. However, the medium of the source material, and the expectations associated with it, soiled it a bit. There were too many annoying distractions to allow me to enjoy the good things.