Godzilla was a metaphor for whatever the audience wanted it to be, natural or humnan-made disaster.
This movie was about a kamikaze pilot that survived. Huh? Wasn't he supposed to die? Then he survived the first time Godzilla appeared. Then he survived the second time Godzilla appeared. The survivor guilt was eating him alive. Was he going to live or die when Godzilla appeared the third time?
This Godzilla was awesome, especially when it powered up to shoot the radioactive ray. It would've been great to see the special effect in a movie theater.
I thought the movie would explain why it was called "Godzilla Minus One". A lot of Japanese brands were named strangely, for example, the clothing store "Niko And...", but the movie never explained. Oh well...