Ouch, that was a rough first episode, even as someone who've read the manga before. The contrast between Takopi's cute design with the bleak, rough style of everything else really captures the contrast between Takopi's innocent and the much more bleak reality of both Shizuka and Marina.
They also drew Shizuka's house with a messy background to reflect how messy the reality is. Shizuka's depression isn't as simple as being bullied, her home was a wreck because of her mother is allegedly having an affair with Marina's dad. There's also a glimpse on Marina's side also having a broken home because of it.
This is a wonderful adaptation, with not only a great animation but also great cinematography. I like how they depict the bullying with Marina and Shizuka with that split view. I also like how they show Takopi's first-hand experience with bullying and how scary it looked at the point of view of the victim. There's also this beautiful sequence of Takopi hesitated on helping Shizuka facing Marina.

Oh boy, I'm not ready experiencing this the second time

Kyoani did it again! That was vibrant and fluid animation. The use of thick, non-uniform line art combined with saturated, uniform color really set City apart from other currently running anime. The simpler color and line art made it much easier to animate big and expressive movement.
They also go and beyond in animating all the visual and sound effects. It made everything more coherent.
Definitely the best animated anime I've watched in recent years.