Added:
Fran Bow
Freedom Planet
Frozen Synapse
FTL: Advanced Edition
Future Unfolding
Galaxy of Pen and Paper
Earth 2150
Enigmatis 3: The Shadow of Karkhala
EXAPUNKS
Fallout: New Vegas Ultimate Edition
Figment
For The King
Fossil Echo
Frozen Cortex
The Elder Scrolls III: Morrowind GOTY Edition
The Elder Scrolls IV: Oblivion - Game of the Year Edition Deluxe

Updated:
Enclave
Earth 2160
Finding Paradise
Party Hard

Removed
Swords of DItto

Just in case you missed my post:

https://www.gog.com/forum/general/games_that_treat_gog_customers_as_second_class_citizens_v2/post719

I know I did, apologies.

Septerra Core added. :x

Edit:
Doorkickers.
Multiplayer has been added.

Just one additional information. A few months ago I already contacted the devs about the missing Figment Soundtrack on GOG.

Here is the reply.

So there is still hope.

Good to see they cared in the end.

Darkest Dungeon still listed but it's up-to-date.
Probably missed this https://www.gog.com/forum/general/games_that_treat_gog_customers_as_second_class_citizens_v2/post724

Oops, will do.

Removed
Darkest Dungeon and
Door Kickers, both up to date now.

Yeah. :D

Door Kickers' Linux version is still 1.0.9

Made a support request for that today.
...and another support request for the outdated Linux version of Broforce...
...and another support request for the outdated Linux version of Victor Vran...
...and another support request for the outdated Win and Mac and even more outdated Linux version of Don't Starve.

Four open tickets. Let's see how long GOG support will take to react...

edit: Make that five open tickets. Not Linux related, but I've filed another one for the missing updates and missing price drop for POLLEN (price for the game was permanently dropped from 25$ to 10$ on Steam two years ago, but it's still 25$ on GOG)

Thanks, my bad! :)

A Hat In Time's GOG version is not getting the Online Party feature in it's latest DLC.

Thanks for taking the time to do that. I've emailed Haemimont regarding Victor Vran myself a month ago, didn't receive any reply at all and they're usually very supportive of GOG.