I’ve come to the conclusion that the Coppelion anime feels like the Coppelion manga with its edges filed down. I don’t mean just that they’ve removed all references to nuclear radiation, or that if you add up all of the elements of each version that one is more “serious” than the other, but that there’s a distinct difference in presentation.
Though the manga is more overt with its criticisms of nuclear energy, at least at first, it’s also wackier in a lot of ways. Amidst the tragedy, characters make wild and contorted faces almost like they’re One Piece characters, and there’s even more fanservice to boot. Aoi, who comes across as more cutesy in the anime, has a greater degree of comic relief in her in the manga, and I think it just has to do with that sense of exaggeration.
Here’s Aoi in the anime:
And here she is in the manga:
Also note the difference in Ibara’s facial expressions.
I think in some ways, this difference in feel does more to change the contents of Coppelion than even the censoring, like the wackiness adds a certain element of permeating ugliness to the story which helps to foreground the social and environmental issues a bit more. That might just be my personal preference though, and I find as the show gets into the second arc it starts to adapt the original material better.