Hey so i'm new to using GOG and other similar websites, kind of new to achievements also. So i got battlezone 98 redux and its telling me in the game that i unlocked the achievement but on GOG galaxy it doesn't show up at all? Can anybody help me out?
-Thank you, Joel

Contact GOG directly or post it here:
https://www.gog.com/forum/general_beta_gog_galaxy_2.0
Or... wait / restart Galaxy / restart your PC.

thanks a lot, i will try both!!