Hand-drawn graphics

Hello, I just recently came here and still don’t quite understand how everything works here, and my English is not at the best level, now I’m writing through Google translator (it doesn’t translate Russian very well)

Regarding modding, I, as a person who, although he is fond of it, but does not have sufficient experience and understanding of the issue, have one question. Is it possible, technically, to make a mod for the game that makes hand-drawn graphics? Like some kind of CEL-shader or watercolor graphics?

I think it should be possible by changing textures and the used shaders in the game. Those are things that a mod’s .pck file should be able to overwrite. If more complex changes are needed those are a bit harder to get to work.