When I first heard of this anime, I got a little excited, I honestly thought it would be great! I could probably learn something from this psychological horror, and walk away smarter.
When it was over I wanted to cry and throw up, the only good thing about it is that it's only an hour long. The story is anybodies guess, for some reason there are witches, and demons, despite 'pupa' meaning bug or parasite, they should've went with aliens it would make more sense. It's hard to look at the average art style, you know, with all the grotesque organ-eating happening. The soundtrack is alright by itself, though I had to look it up to remember it. I'd say I feel sad for the kids and their abusive parents, but they are essentially gods with regenerative powers so they'll get over it eventually.
Stay away at all cost. Though you're probably interested in it by this point, and curiosity is a powerful demon, just at least know what you're getting into, and have a bucket nearby for the throwup.