I didn't see a thread for the movie by its own, so I hope it's alright to throw this here -
Next to King Kong Escapes, this is easily Honda's most outlandish genre film. I'd have quite a hard time trying to explain it to anyone who wasn't already familiar with Toho's output in this corner of cinema. It's such a bizarre movie... I wouldn't say it's for beginners in any way. Again, I think you have to be familiar with Godzilla and co. to really appreciate the weirdness of it all.
Just two things I'd like to point out -
1) From what I've read in Eiji Tsuburaya: Master of Monsters, a US producer pulled out at the last second, which shrunk the budget to a certain degree. What I mean by that is Tsuburaya really excelled at prehistoric reptilian kaiju, but when it came to mammals he never quite nailed it. All the creatures in Latitude Zero are really odd and ratty (the Bat People are still kind of freaky though). And then those Kong suits..
2) What's up with that ending? I still can't wrap my head around it. I know the movie's a fantasy, but it always feels like I'm missing something that isn't there. Even when I re-watch the movie with that in mind it's always so jarring with the rest of the story.
Exterminate all rational thought.