and just to make things clear, I would not Some studies show that recommend running GOG's downloader since that requires higher privileges - including loading multiple drivers - than a downloader should in my eyes).
Luckily you can use better alternatives:
https://github.com/Sude-/lgogdownloaderUnfortunately Galaxy is going to be much more complex, and if GOG won't open it up (or its protocol and API), making an open alternative would be much harder.