Really didn't expect this to be good for some reason. Probably because this is a very unusual style for someone like Nihei, but he somehow manages to pull it off either way. Good stuff.

>Story
It’s fairly decent. It’s your classic revenge story in an interesting, but sometimes way too subtle world.
The story follows our protagonist, Etherow on a quest for revenge against the oppressive Empire for slaughtering his comrades and destroying the settlement he lived in.
The world-building elements get the Nihei treatment, as in: most of the stuff gets left out unexplained, like the origins the relics, or the automatons, or the regular frames. Where does all this come from? Well, at least we get explanations as to how these things actually work and affect the world, unlike in Abara.
Then again, this manga IS ongoing, so I’m waiting to be proven wrong on the statements I made. But for now, especially after Abara, I’m not a fan of this style of world-building. Although, to give it credit, it’s miles better that the stuff I got while reading Abara. 6/10.

>Art
I’ve been hearing some people say how Nihei’s art degraded, but I disagree. He’s trying out a new style, which is very fitting for the sort of world he has created on top of being gorgeous. Even if it’s objectively less detailed, I think it’s got its’ own soul to it. Simply put, the art is fantastic. It gives of a clean, fragile, almost crystalic kind of feel, and its’ simplicity works to its’ advantage.
My only gripe with it, is that the character designs, albeit cool, are starting to feel a bit same-y, since most of the characters wear uniforms and their regular frames are made out of the same material. But that’s barely a problem, since they’re still very good. 9/10.

>Characters
I’m really torn on them. Most of the enemies, apart from maybe Yiyu, Biko and the main baddie are blank slate jobbers and the protagonist is way too OP. He barely even struggles when he deals with his enemies. This has been a problem in Blame as well, except in Blame it’s not a problem at all, because Killy isn’t out to get his revenge on a supposed powerful and oppressive government, unlike our MC here.
The characters in general have goals and motivations. Etherow wants to get revenge on the Empire because they killed his friends and his mentor, whom was like a father to him. Titania wants to stop the Empire from conquering The Core. The Emperor wants to conquer Aposimz. But what do they have going on besides that? Barely anything. Maybe the main villain doesn't count right now, since he's just barely been introduced, but the MC and Exposition-chan over here have no excuse. The only thing I can remember about Etherow and Titania besides their common goal is that one likes grape fruits and the other has two scenes in where she "pisses" and makes the MC drink that in order to restore his abilities. Phenomenal.
What about them having their own unique philosophies? What are their personalities about? What are THEY about? Say, what about if Etherow wasn't fond of being a regular frame? What if him becoming that was a split second decision that he regrets? Wouldn't that make for a more interesting story? You could also develop this trait towards the end, where he would realize that being a regular frame doesn't get in the way of being a human, or something cute like that. Just feels to me like something like that would make Etherow a more complex and deeper character, but that's just my imagination going off. Anyway, I really hope the author touches up on the feelings and personal qualities of the characters more in the later chapters.
It’s got some good characters in it too, though. Like Kajiwan, a village ruler who’s jealous of Etherow and Keisha for their regular frame abilities, he works very nice as a side character. Titania and Keisha show potential to be great characters, as well as Biko. 5/10.
[MILD SPOILER]
Edit: right as I write this review, chapter 21 has Etherow actually fail and fall into a coma of sorts, on top of that we get a little more time to look at the supposed main villain of this story, which was really nice to see. Kajiwan is also becoming a much more interesting and vital character now, with all the cult stuff going on. I'll bump the score up to a 6/10.
[MILD SPOILER END]

>Enjoyment
So far this manga has been amazing to read, quite honestly. I love the vibe it gives off, you can actually immerse yourself in the atmosphere of it so damn well. Maybe it’s the style that’s giving it this unique type of feel, or maybe it’s all the quiet moments that we get to fully observe the locations this world has, or maybe it’s all the creative and fun, albeit quite lacking in explanations of them, abilities that the characters have.
There’s really a lot here to enjoy in this manga, even if I can’t in good conscience ignore all the technical mistakes of it. 9/10.

>Overall
I like Ningyou no Kuni. I like it a lot. Sometimes it gets way too shonen for me, but I can forgive that. All the cool designs, all the gorgeous and interesting locations, all the soulful covers. Even if the story and the characters may be just a tad lacking, It’s still very interesting to read, at least for me. And it’s definitely so much better than Abara. 8/10.