This is literally a commercial for a series obviously there's not going to be much depth in story or character development.
Pros: Looks promising.
Cons: Chibi-children they need to die.
It was a pretty good preview I guess the first episode and basically to watch the show which was alright was okay not a bad series but not a thing that I would instantly watch no matter what . but it was interesting enough to actually get me to start watching the series and I'm very glad I did. not really worth the watch but I mean hell it's 58 seconds, why not watch it.
Super fun and creative anime looking at the inner workings of the body. Very informative and endearing.