Got a response from the dev

"I have been looking into getting Paper Sorcerer onto GOG. I'll update when I have good news. It just takes time to do the paperwork and for that to be processed and approved, etc.
Feel free to write anytime you have any questions or comments, I appreciate the feedback!"

I might end up buying it elsewhere for now and get it also when its on GOG. At least the dev bothered to reply :)

I'm really enjoying this game. It would fit right in on GOG. Very well done.

Game is definetelly worth the $5 price tag. The Pen and ink textures are very well done. The RPG elements and battles are very deep and very stategic. There are puzzles and a nice story. Would still be worth it at 2-3 times the price. Very well done by the 2 person team who developed this game.