I like it. It feels free and unconstrained.
You might add some blue for the rivers and seas but the style is very pleasing. If the white ribbons are rivers you may want to disconnect the two systems where they join above the central forest. ROBA is the recognized river cop but I think the water in that joining section (right above the central forrest) would either go east or west towards one of the river mouths. I don't think it would stay continuous river across the middle.