It seems that you're using an outdated browser. Some things may not work as they should (or don't work at all).
We suggest you upgrade newer and better browser like: Chrome, Firefox, Internet Explorer or Opera

I can't find the option in the menu, nor can change it in GOG Galaxy.
Anybody know how to change it?
The shop says there are several languages, but once the game is in the library there is only English available.
Is there really only English?
Have a look inside of the game installation directory.
There you can find a program called "language_setup.exe" that allows you to change the subtitle language.