Even the serious Godzilla movies — like the 1954 original parable about the horrors of the atomic bomb — are fun, in some way. It’s a thrill to watch a giant monster topple buildings and crush tanks.

When the Bilusaludo and Haruo disagree over the best course of action to defeat a seemingly unstoppable foe, their argument hinges over maintaining humanity. The Bilusaludo want to become one with the ...