How to download your GOG library
I wanted to backup all my games from gog. So i found this handy tool.
You need to get the lgogdownloader either from github or via your package manager
$ lgogdownloader
# provide your email, password and code
$ lgogdownloader --language=de,en --update-cache
$ cd YOUR_DOWNLOAD_DIRECTORY
$ lgogdownloader --language=de,en --download \
--subdir-game gamename%/%dlcname%/%platform% \
--use-cache --save-serials