You seems using two size of felt, and i think none of the two are black enough. When zooming, we see transparency, shades of greys in the lines.
Sometimes you swap from one size to another, and i think the transition is sometimes not very good.
Trunks of your woods are sometimes too inclined (near Seckur for example, or between Achbe and Tonk)
Sharpen your lines for the city symbols, it's drooling.

But even with all this said : I like the global design! When not zoomed, it's very good!