Episode 8 should have been episode 1, and it could have set up the the anime to its greatest potential. Episode 8 is beautiful, poetic and mixed the right amount of aspects, comedic and tragic, but majority of the previous material pale in comparison. The anime improves a lot past episode 8.
Judging solely from the adaptation (no idea about the manga), Hanako is a frustratingly inconsistent anime. I really wanted to love this, but the constant mood shifts are rather staggering for me. Sometimes, it gets to be insufferable and just hard to focus on. I believe it's because the heavy art style contrasted the moods and even the story progression very poorly. I do believe the art style is the best aspect of the anime, by a large mile, if not THE art style of the season. Then again, the anime can literally be a mess that was a strain for the eyes to watch. It also made things quite difficult for me to assess individual aspects.
Here goes anyway.
I want to present my biggest reason of being uncomfortable with the anime... the "fanservice" aspect of the anime, showed by prepubescent-looking people. This is not about "degeneracy" and I have to emphasize that. Normally, I am very forgiving of fanservice with anime (and I am guilty of being a shota fan), but the anime just felt awkward and forced in this regard. The worst part is it contrasted very poorly with the serious tones of the anime, especially with the development of characters. It's almost consistently feeling like there would be an amazing pull-off, only to have a baffling comedic choice in one side. It's like a mix of multiple intentions that did not mesh very well, and it made the depiction of characters suffer or just too slow in pacing. My personal experience and even appreciation does improve significantly in later episodes. I give this a very annoyed 5/10.
Art Style 10/10:
This is the art style I feel would have benefited the likes of Soul Eater so much. It's not even just the heavy strokes, it's also the presentation of scene by scene, frame by frame, and a lot of minor details of motion. Very charming and powerful even. The trailer sold me so well, and the anime definitely delivers!
Sound Design 9/10:
I find the ambience very fitting and naturally entertaining. The contrast of the OP and ED is also a nice reflection of the anime. Solid, actually memorable. Voice actors served the characters very well.
If I think about it, the setting honestly could've been boring if not for the striking art style. But to give it a separate judgment, the setting is rather simple. Most of the anime spends its time in the school and a spiritual realm (this one being naturally flexible). The design details are strong, and the portrayal of information is immersive and charming. The anime works in this aspect in a sort of episodic manner, and it does so to a great benefit. It plays along very well with the mystery appeal too.
The story is... okay. Most of it is represented through the characters anyway. So much of the things I could say here will just reflect a lot of things that were already said. Intriguing could be a more proper term, but I think this season as a whole lacked punch. But that doesn't take away from its potential. I will definitely watch more of this universe. Then again, I'd suggest this more as a "comedic mystery with shock value" rather than something dark. It's just a difference in pace.
I would easily recommend the anime just for experiencing the art style. However, I would suggest new viewers to bring no expectations to have an entertaining ride.