My art process is kind of simple really.
Sketch (on Procreate) -> Trace it and turn to Vector (on Figma) -> Add lightmask layer (on Figma) -> Then the unity magic, the tutorial can be seen on link below.
For making sharp shapes, I highly recommend studying Samurai Jack artstyle or just search sharp artstyle on Pinterest, there's a lot of references.
You could use other tools ofc for sketch and vector.
The highlight and gradients from sprites that can change colour was inspired from this (minute 7 to be exact):
So for sprite with the same target sorting layer as the light, they will produce that shiny light.
Then finally about stylized debanding.
I just know about debanding right now haha.
The film grain actually is just "let's try it here."
Like literally no other meaning.
I guess the film grain doesn't work, so maybe I'll remove it on future updates if the development continues.
Anyway, thanks for playing!
I'm grateful that the first wave is easy enough for you to not miss any parries.
If you're interested in this (technical) artstyle, try learn about sprite masking and lighting first with extra Post Processing.
Lastly, I'm also still a learner in technical art, so it's cool to find another who interested in it.