A Hat in Time - I can confirm that achievements are either broken or not unlocking at all. Specifically with the [i]Put a Badge On It[i] achievement, a new game did not unlock that particular one, but loading a previous game and equipping a random sticker seemed to unlock it.

Time Piece collections seem to be broken, as I collected all Time Pieces in the Battle of the Birds chapter today and did not receive the achievement, even after quitting and reloading the save.

Thank you, I will try to contact the developers to see if they intend to do something after all this time. If you want, I found the link to their Discord that might be useful to contact them, the more the better: https://discord.com/invite/AHatinTime

They seem to have fixed these two achievements, can you confirm that?

Someone tipped off the fictorium developer you were broken.

The developer responded but he got no response in June.

https://steamcommunity.com/app/503620/discussions/2/2280456883452249930/

Thanks, interesting. In the meantime it seems they have answered him so with a bit of luck he will be able to solve the problem if the bug is still present.

Regarding the missing achievements for "Lair of the Clockwork God" I would like to add that the devs told me in discord that they tried to implement them into the game but did not manage to do so yet. Still there's hope.

"Gog achievements didn't work. I was unable to ascertain if it was my end or their end, so I fired off an email and didn't hear back. To be honest GOG sales are so astonishingly low it's not cost effective to spend time looking into it, but I'll dig into it next time I'm putting a patch together."

Thank you for this news, I hope they can add them sooner or later, the game deserves it.

Hey hey, it's me again, with another batch of broken achievements.

Kingdom of Amalur Re-Reckoning
Perfectionist

Reported - no responce, no patch... yet

Blades of Time
Out of My Way

There is no Online play in GOG version, so this achieveemnt cannot be unlocked. Reported aswell, and aswell no responce, no patch *sigh*

Project Hospital
I choose you...
Wait, is this a bar?

Reported - Devs are aware of it, promised release a patch soon... Although it never happend.

Liberated
Hacker

This one I'm not so sure. It is either broken or pretty much impossible without easy access to them and having any sort of timer in game.

The achievements: "Procreator" and "Perk-ic Victory" for Star Renegades are broken.

The developer has acknowledged that they are broken, and mentioned that on STEAM, the latest "beta build" fixes these. However as of writing this, the patch for the main version still hasn't been released, and even when it happens on STEAM, it will lag by 2-3 days before it reaches GOG.

Galaxy Overlay broken for Legend of Heroes Trails of Cold Steel 2 since Feb 2019 (update 1.4.1). Preventing achievements obtention and other galaxy features while game is running (like screenshots)

See more on the game gog subsection

Thank you! Hopefully it won't take much longer, but I'm quite confident that the fix will arrive on GOG as well. In case let me know as I don't have the game, so I can take the game off the list.

And thank you! XSEED has made some fixes to their games on GOG recently, I hope they can solve this problem too. If possible can you send them an email with as accurate a description of the problem as possible? Let's see if they can do anything. support@xseedgames.com

All reported bugs have been added to the list on the forum.
And now some more good and bad news:

Kholat now has the achievements.
Ys I and Ys II have working achievements again, but the final achievement of Ys I is probably broken.
The broken achievements of Life is Strange should now work.
The missing achievements of the DLC West of Loathing: Reckonin' at Gun Manor should finally be added to GOG and they should work.
I am waiting for some more feedback to update the list respectively.

Small Update
I just got a reply from THQ.

Of course!

As an update, apparently there was a typo in the game's code, which prevented the proper tally up of the progress, so when the update goes live the progress on the broken achievements will start from zero. It's unfortunate since the broken achievements are time consuming.

Another small update:

Blades of Time
Out of My Way

Bugged achievement has been removed from GOG version.

and something I forgot to mention before

Crossroads Inn

All achievements are currently bugged. Devs have been informed long ago, no responce, no fix.