My reason for giving this anime a 0.5/10 are the following reasons:
3-5 mins per episode. Some animes I have watched are able to use that amount of time successfully (specials, etc). For Pupa this is not the case. This kind of anime requires at least 25 minutes at best.
The anime adaption somewhat follows the manga (except ep. 7 to 12).
However the anime version is completely shuffled about. It follows the story (kind of) 1 episode and then the next episode, goes off to a completely different chapter that is later explained rather than following it correctly as the manga.
Having only 3 minutes of show time at the max, the story is rushed too fast leaving the viewer confused and disappointed.
Some of the scenarios are altered completely as well, which is not great idea and a waste of good source material. Examples: How Utsutsu and Yume encounter the creepy thug, Maria being pregnant in the shower scene (did not happen in the manga) or Where Yumes was strapped to a chair and blindfolded, then was somewhat rescued by "Yuu".
Tho the main characters are present (expect "Yuu" for some reason, yet he is seen in the OP - green wallpaper). However the side character are either not shown or not given their full and proper roles as they were originally in the manga.
OP and ED are very dull and depressing.
In one scene, where Yume is eating Utsutsu the music plays a carnival theme music. That was WTF.
I had high hopes that it was going to be a great anime, I thought the company Star Child was joking around about it being 5 mins per episode, but in the end it was a disaster. Bad anime adaption indeed.