Before I begin my review, I want to say that I am not the most serious critic. I only state my opinions in my reviews, and I don't shove false facts down peoples throats saying the show is bad. With that out of the way, let me start the review.
Kami nomi zo Shiru Sekai: Flag 0 was not really needed, all there was to it was Elsie having a conversation with Doukuro Skull about going down to Earth and stuff, so it wasn't really needed.
There is literally not much, the closest you would get to a story is them mentioning a "human who can
conquer anyone" which, is obviously Keima. But, other than that, the story doesn't really exist.
The art is great as always, I love the art style and animation to this series.
Was there music playing in this short video? I don't even remember.
There's only two characters to mention, and I like Elsie but I'm never too sure about Doukuro Skull, she's just... hmm... I'm not sure. Besides voice acting someone from Gintama, she's... not that great, but she's a great addition to the series...? I guess.
This was just a not-needed clip that was added to the series. You could have just read the start of Chapter 1 of the Manga and then things would of been done with. Or just read the whole series, cuz' it's fantastic.