A very strong entry! I LOVE THE ART. I thought at first the cover art might be from Fantazius Mallare , by Wallace Smith, which was a featured series of public domain work shared during the jam, and then I looked closer and read the credits and YOU DREW THAT. And the ISO MAP TOO!
The Facimil-tree is a very good name for a creepy and great design. I wonder, do they call it 'parent'?
There's very little to critique - this is one of the best entries I've seen.
A few improvements I'll suggest: you could demark the bulk of the summit (hidden by clouds) under the rest of the map layer with just a change in greyscale background, and that would sell the 'three islands floating around a flat-topped summit' just a little bit more.
The subtle use of color in the iso map is much appreciated.