Lake Nyoma has two outlets. While not impossible, this is very unlikely. Such arrangements don't last long, geologically speaking- eventually one outlet erodes a bit more and "wins." (Or, it could just be one hell of a coincidence, or the result of magic, etc.)

OTOH the river/lake system in central Aengvald has no outlet. Nor does the system on Vorenth. Nor Lake Pybo on Sereche. Did you intend for these to be endorrheic lakes? That would presume a drier climate, which your map doesn't resemble. If a river feeding a lake is large enough to be seen on the scale of the map, there should logically be one draining that same lake that is also big enough to be seen. Unless, as I mentioned, the lake is endorrheic for some reason.

The routes of the rivers on the very skinny island of Galloway strike me as unlikely.

That's a heck of a density of lakes, unless you're going for a look like the lake country surrounding Hudson Bay or your theorectocal geology otherwise explains it. (Most people put in too many lakes.)

Yes, a scale would be helpful. Since we can only see a compressed version "six pixels to the mile" doesn't help us much...

The only port that I see on the outer side of any islands is the one on Vorenth. Is there a reason for so few? Is there no outside trade?

I do like the light ground coloration. It reminds me of the map of Central Alemnia that Daelin just posted, where the ground is bone colored. One hell of a map, that.

I'd make the political boundaries a color other than black, so as not to confuse them with roads.

Don't take my criticisms too sharply- I have certainly never posted a better map than yours...