Did everything in game except for the 25 minute challenge in Sibirskaya-7 Junction, unlocked everything, purchased all skills and upgrades. Completed all requirements for the achievements, including the secret ones.

The Growth achievement (buy 28 skills) would not unlock. Oddly, Evolution Achievement (buy57 skills) did.

That's two SGW titles in a row I can't 100%

Do the Devs visit these forums?

I'm running Windows 10 64-bit, Galaxy 2.0.

Anybody else run in to this?

That's weird. Had no problems with unlocking it in my playthrough. I think it may be related to one of the recent patches, but not so sure about it.

I'm very much doubt, that any Dev is visiting GOG's forum. Although, to make things even worse, 100% achievement doesn't work in this game as well.

The GoG overlay doesn't work in this game, When I tab out to check my achievements I can see that I do get them now, but the overlay + achievement popup doesn't work.

Also I just played through Metro Exodus and the overlay + achievements worked as intended in that game, So there is something wrong/broken with this game + gog.. :/

EDIT: The free weapon skins doesn't appear in-game either, I've tried the manual download but it won't work :(

Second EDIT: to be able to use the free skins I had to go into GoG Galaxy > Games > Sniper Ghost Warrior Contracts > !Downloads, and manually install every skin one at a time.