I'll throw in my kudos again - I definitely agree that the forests look incredible, and while I keep thinking the mountains are a little too linear, I remind myself that it's an impact crater, and normal rules don't apply.

If I were to pick at nits, however:

Looking at the scale on your previous map - that's one hell of an impact crater. It looks like ~500mi (750km) - more than twice the size of the Vredefort crater (largest confirmed extant crater on Earth) and nearly 5 times the size of Chicxulub (the theoretical dinosaur killer at the end of the Cretaceous). Assuming this crater was formed any time in recent memory, it would have caused one hell of an extinction event - possible fodder for the campaign history, perhaps?

There's also a bit of a question why an impact crater would form an island - most sea-bound craters are completely (or at least mostly, as Chicxulub) sub-surface. Maybe the surrounding sea is relatively shallow? Or maybe the crater is old enough that the ocean currents have worn away some of the ejecta? Or maybe it's not so much an impact crater as a volcanic caldera - but then why the prominent central peak uplift? A caldera could form a central peak, but it's more likely to be a rough mound or hill than a sharp peak... OR maybe I'm just being too OCD...

The coastline glow still seems a bit distracting when zoomed in. It's fine when viewing the map as a whole, but zooming in the glow just doesn't seem to "fit" with the rest of the map - it feels a bit artificial to me... too regular, perhaps? Maybe try using the technique from RobA's artistic map tutorial (post #8 ) - blur the sea mask by a bit, then use displace filter to give it a wispy irregular look? I've also wanted to try using the sea mask as a selection, then using Stroke Selection with a big grungy brush and a lot of jitter (maybe a couple times with a low opacity) to give it a more random appearance... OR I'm just way to hung up on continental shelves for my own good.