I noticed that the Gog Galaxy now displays the achievements counter, but they do not unlock when I play the game via the same program. The store page doesn't mention achievements yet. Were they added or not?
EDIT: It does count the progress, and they are in the Gog Galaxy program. But they do not unlock when I am in-game.

Yes, I found the same thing. Achievements didn't work until today. At least for me. And yes, I launched game via GOG Galaxy.

Did you enable the synchronization between local files and cloud? Because it always corrupted the game files, therefore I am not sure if it works now correctly or not.

I don't know. Not sure. May be you can get achievements only if running game withot Galaxy. May be not.
Hm, may be you have to try game without GOG Galaxy? and then check with GOG Galaxy.
I got some achievements today(as said).

There is no need to enable the cloud synchronization. They unlock without it. Although, crafting the normal, epic and legendary artifacts doesn't unlock for me. But other achievments do unlock. What a pity that the achievments don't unlock retrospectively upong entering the game.