Kenji Miyazawa is known for writing children's books and it shows here. This is basically a movie for children, only a bit more challenging.
It's mostly apparent in the main character, Budori. He would be an ideal role model for a child: caring for his family, studying diligently, even WANTING to study, working hard and persevering no matter what. Making a heroic decision in the end only tops it off.
Except he isn't. He shows no attachment to literally anyone but his little sister. Not even his parents, let alone his employers and teachers. Earlier I wrote that he cares for his family - well, technically, he does; after all, his sister is part of his family. But that's really the only person he truly cares about. Not that he isn't interacting with everyone else; in fact, he is clearly distraught when both parents leave the house, but he doesn't even remember them afterwards. Now imagine the fate of those he only had brief encounters with.
On one hand, this can be seen as a good thing, we really don't need yet another idealized main character. On the other hand, this is the biggest flaw of this movie. Since there's little interaction and no attachment to any character, most of them feel like tools for making Budori spew out some lines or make some actions and once they did their job, they are disposed of, so quickly that there isn't enough time for the viewer to care about them. This is not a good way to draw attention.
Speaking of drawing attention, the overall story is not really good at it, either. It IS solid and rather well-written, but not really much is going on here and it feels almost pointless. Don't get me wrong, I didn't dislike the story, but I didn't really like it either. There is a boy who went through natural and personal disasters in his childhood days, managed to persevere, went to the big city, studied and saved many people from another disaster. And life goes on like it always did and always will. That's one part. Another part is the inner world of Budori, his development, his role in this world and his trying to come to terms with life and death. I personally feel this part is better done, because it actually makes use of the medium and relies heavily on symbolism, art and animation.
And this is where the movie truly shines. One can literally see the amount of work that went into the art and it's really amazing. The first half of the movie is set in the countryside, so we get to see some really beautiful landscape panoramas. The second half is the city of Ihatov and while the art still remains beautiful it isn't nearly as amazing. Besides, there's quite some CGI in Ihatov, it's quite bad and does stand out because of that. Also, it feels like the movie tries really hard to be a Ghibli - but there's more to Ghibli than just the landscape art. Nevertheless, it's all really impressive. Is the mood happy and complacent? It shows in the art. Is there something new that just came to life and shines brightly? It shows in the art. Is something deteriorating over time? It shows in the art.
It's even more impressive when the movie deals with Budori's inner world. Here everything becomes surreal and it's hard to tell whether the events should be taken literally, whether it's just a metaphor for something or whether it's simply embellishment. It's even harder to tell whether those scenes depict actual events or whether it's all in Budori's head. Those scenes were what I enjoyed most in this movie.
To sum it up, while this movie isn't outstanding, it's really solid and does have some value. Do show it to your children but be prepared for their complaints when their attention starts wavering.