If you loved Invasion of the Neptune Men, try Gamera vs. Guiron
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.
What they share
Theysit in Action / Adventure / Science Fiction territory. If that's the register that drew you to Invasion of the Neptune Men, the second film will land in a comparable space — through a different lens.
What Gamera vs. Guiron is
Two kids stow away on a spaceship and get shunted to a planet full of alien salad days gone grotesquely wrong. Gamera jets in to babysit while a crustacean buzzsaw monster tries to mince their brains. The whole thing feels like snack-time left unsupervised.
Ask 
ChatGPT
Claude
Grok
Le Chat
Perplexity
for a deeper bridge
ChatGPTClaudeGrokLe ChatPerplexity