I was going to do it by myself and publish it later but since I had the idea, for one or another reason I was unable to play at all (work, personal issues, etc, etc, etc) so I wondering if the community could share their findings in this subject.
I'm specially interested (as probably many others) to know if old games (BG, FO, PT, etc, etc) have achievements...
Thanks in advance to anyone who can help.

Tug of war with the cyclops, if you fire your gun you've achieved something.

From the ones I played, GOG versions of Defender's Quest and Magrunner have achievements.

Depends on what you really want though... they they have built in achievements yes. Banished has them too.

But if you want Galaxy achievements then there is the Witcher 2, Witcher 3, Witcher Adventure Game, and the Telltale Games.

The cRPG games have achievements at GOG

Divinity: Original Sin 2
Pillars of Eternity 2: Deadfire
Pathfinder: Kingmaker

Possible Sources on Gog are:

https://www.gog.com/games?page=1&sort=popularity&feature=achievements

https://www.gog.com/forum/general/ingame_achievements

https://www.gog.com/forum/general/list_of_broken_gog_achievements

Also each game on Gog has it own forum - you can research or ask there as well for this specific topic.

Outside Gog - there are separate wikis for pretty much any game nowadays, and you can also check them out there as well. e.q. for Baldurs Gate: https://baldursgate.fandom.com/wiki/Baldur%27s_Gate_Wiki

At least you can check out Steam Community Hub (for specific game) - there are achievement guides etc.. This will help you too for sorting out if a game has achievements or not.