Story:
The story that this show provides you with definitely provides some social commentary on society as a whole. It carefully puts together this world that Yusuke Kishi has made. You slowly learn of this world's customs and this world's traditions. You go in the show as a foreigner of this world and come out of it as a native. And I think that is the best way to describe this show.
When you start watching, there is a lot that you just don't understand, and some things may come off to you as weird. That is because you are a foreigner of this world, and depending on whether or not you wish to stay in this world, you will have to grow used to some thing that are different. So in world building and storytelling, I definitely will give an A.
Art & Sound:
As for the art of this show, I'd say there are some problems I had. The art itself leaves something to be aspired for. It is not hard to watch by any means, and it even has some beautiful moments, but as a whole I felt like it could have been handled better. The character designs felt very plain. It looks as if they all the main characters share the same face and body types, and the art style was not easy to get used to for me. It was different, and although that is not always a bad thing, it was in the case of this show.
The soundtrack itself was amazing. I found it absolutely fitting for the show, and it pushes certain emotions out of you. The ED itself, is one that I will go back to listen to time and time again. The music is really the best fit for the show. And for the voice acting, I'd say most of the voices were fitting except in maybe the later part of the show. The voice actor changes do affect the character somewhat, but the quality of the voice acting does not waver. The voice of the main antagonist is really fitting too. (By the way, I watched the sub only.)
Characters:
The characters in this show are definitely well written. The situations that they are put through, are also situations that the viewer goes through and because of that, you grow to care for them more. You can tell what emotions are between which characters, and because of that you understand the importance of each character. Although the characters all live in a different world than you do, you can still relate to them because they are humans and they still show the emotions that we all have.
Overall:
Although I feel this show fell short with some of the art that was portrayed, it really excelled in just about everything else. It may not have been entirely perfect, but to me I felt it gave me something that I just can't get from any other anime ever. And that is really saying something. Each episode has a way of making me want to watch the next and that is just what I look for in a show. (Not to say that cliffhangers are the best, but when they are pulled off right, they really are great.) So yes, I can see this as one of my favorite shows, but I think rewatching it is something that I would have to think about. It's not really a show that you can experience twice. It was really great as it is though and I would suggest it to anybody who loves, not only anime, but stories in general.
