Hi there!
As the title [edit:does not ^^] imply, there are several bugged/broken achievements.
Especially those achievements counting the boss kill count.
Anyone else having this issue?
Regards

You should contact gog support, i haven't played that much, but contacted them to ask why year of the ox and big spender weren't unlocking, since they just require buying anything. They contacted me saying they'd fix it, and the achievements unlocked fro me, but since i haven't played much ore, i can't talk about the rest of achievements