These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Fantastic Planet
Adaptation Displacement: Yeah, this is actually based on a book, Oms en Serie, by Stefan Wul. Granted, it never got translated into English, until 2010 - 58 years after it was published.
Cult Classic: Usually shelved in the "cult" section to boot.
The fact that it was brought overseas by Roger Corman, the grand master of cult flicks, also helps.