Ahhh... Where to start...
Story: 6/10 - The plot overall is a "OK" at best BUT, the ending left me with a very bitter taste in my mouth, many intelligent characters reaching stupid conclusions,
the author in my view uses "science" in a very distorted way, furthermore he tries to approach about "religion" but I can't expect so much from a Japanese when the subject is "religion" and his distorted way of dealing with the subject, I won't go into too much detail, the other topic addressed in the LN is his view on "technology" it is very distorted, as much as the work wants to convey a message of hope, seeing the characters go through a lot of despair, this for me was very unbalanced, with the sides (Empire & Kioka) that it addressed in the story.
Art: 5/10 - I found it very inconsistent, the anime did a great job, and the novel as it went along, it was very different from the age of the characters with the art shown.
Character: 8/10 - For me what carries the LN on his back are the characters! And how charismatic they are, their interaction and their "evolution as a person" were great, but we have the problem at the end of the story.
Enjoyment: 5/10 - I was loving it until I got to the last 3 volumes, I read it forward, I felt that the author was completely lost in his story.
Overall: 5.5/10 - Quoted the points above, and how pissed off I was with this LN, which had considerable potential, left me pissed and sad at the same time, sad for what has already been mentioned, and pissed at having seen this story played in garbage.