A lousy adaptation of the 1973 manga of the same name, is mostly remembered because of a pretty specific sequence (shocking in animation's standards) which is sandwiched in an otherwise unremarkable and slow film. You're better off reading the source material or watching Grave of the Fireflies, an emotional gauntlet that is way better in almost every aspect.
A movie adapted from classic anti-nuke manga series. I think the manga is one of the most important pieces of literature from Japan. The movie doesn't have a great production value and it is not very good. But, it is powerful nonetheless. Netflix says this is a "fantasy" movie. How sad. All the incidents depicted in the movie are based from facts. How sad and maddening.
Solidarity and a sense of community on collective tragedies, that's the message of a film that has much more cultural and educational value than artistic and cinematic. The realistic approach leaves its marks as the bombing on bodies, and that's was remarkable for the animation world as in Takahata's Grave of the fireflies later. The manga is surely even more revealing.