Its has an interesting approach on the Godzilla theme, and I like the story central idea. Yet I found the execution of it to frail, like if it was done in a rush without thinking it to much.
The characters, the dialogues, the way the story unfolds, it´s not bad, yet it lacks some sense in it, leaving you the idea that it could have been easily improved, yet there was not much effort in doing so.
Apart from that, The animation is not bad, it gets the point done, but leaves much to improve. The voice acting could be much better, at least in the Japanese version of it, but again, is not a deal breaker.
Still, i enjoyed enough that I watch the rest of the trilogy, without regretting it.