So Godzilla not only destroyed Tokyo but basically all human civilizations, including 2 aliens civilization, with interstellar travel capabilities, that happened to pass by the Earth but were incapable of defeating him. That's an interesting concept.

The design is great, it really looks good... except for Godzilla that looks like an overbuffed bodybuilder in slow motion.

When they return to Earth, 20 years have gone for them, but 20.000 on the planet. Everything has become adapted to Godzilla and its radiation. Again, interesting, but not developed much. And Godzilla is still there.

The plan to fight and the attack are ok, but not really that interesting as it really moves in slow motion.

[spoiler]After killing it, turns out it was just a baby[/spoiler], good one if not unexpected.

It's a little light on characters. There is basically only one main character, Haruo, and one secondary character that has a real role, Metphies. There's also Yuko, though her relationship with Haruo is weird, he seems to know who she is and try to protect her, but she says she really wanted to meet him, so they had no prior relationship. She's useless anyway.

Metphies seem to not be surprised by what happens, and has he says he has already seen other civilization face the same threat, kinda wondering if he didn't want them to fight because his religion wants them to be punished.

Also we barely see [spoiler]that there are natives running around[/spoiler], and it's all forgotten until the post credit scene. That would be the story for episode 2 then.