Shin Kamen Rider: Prologue

This feels like both Guyver and Kamen Rider done right. Much like the later Mechanical Violator Hakaider from 1995, this takes a kid's show character and ages up the story and visuals. The score is a weak point of the movie and is the fact that the Kamen Rider is not the focal point of the story and doesn't get nearly enough screen time.

I feel like you'll enjoy this if you like '80s werewolf horror movies, even if you aren't familiar with Kamen Rider as a franchise. It starts as one (but with grasshoppers instead of wolves), and then adds mad science, spy tropes, superhero tropes, action movie stuff, and sheer weirdness. It's definitely gory, there's weird fridgey stuff with the female characters, and the action gets a little fatiguing towards the end. But it's enjoyably overstuffed and worth experiencing, if you're up for it.