Every game and date in this thread are tentative.
Game development is an ever changing scape, please don't take anything you read here as absolute certainties. I don't intend for my original posts to have the current hourly up-to-date information, but I will do my best to update them in a timely fashion (daily or at least once a week). I'm always open to rectifications, corrections (especially typos) and suggestions.

Other years: 2017 --- 2019

This thread won't see any updates from me past today, January 1st 2019, and will stay as is. The new thread for this year is linked to up above.

Officially confirmed by GOG games (mostly the upcoming games' list from the front page):

Ancestors Legacy
Ape Out
Biomutant
Bloodstained: Ritual of the Night
Children Of Morta
Creaks
Descent (2019) (Descent: underground renamed?)
Don't Escape: 4 Days in a Wasteland
Draugen
Eitr
Fade to Silence
Forager
Iron Harvest
Metal Wolf Chaos XD
Pikuniku
Soul Saga
System Shock Reboot
The World Next Door

IN DEV:

Besiege
Breathedge
Caves of Qud
Double Kick Heroes
Empires of the Undergrowth
Epic Tavern
Exanima
Factorio
FoxTail
Ion Maiden
Kynseed
Last Leviathan, The
Lovecraft's Untold Stories
Planet Nomads
Production Line
Project Zomboid
Riot: Civil Unrest
Rise of Industry
Sunless Skies
The Guild 3
The Universim
Wolcen: Lords Of Mayhem

For me "in dev" is having access to a game to help make it better for release. When it leaves "in dev" is when I'll take it off this list because it released officially.

Unofficially confirmed games: 2018

Since most of the games will come from:
https://www.gog.com/forum/general/games_that_are_unofficially_confirmed_for_release_in_the_future_part_2/
instead of putting the complete link to the source of the information, I will write the number of the post that came from that thread, you'll then need to copy the above link and add what I wrote after "source". There may be two post numbers written after the source, the first number is the original mention of the game and the second number is the latest "informative" post about it. Any information that comes from another source than the above thread will have a direct link provided. This is to be able to fit more titles in one post.

The games are separated by year it was last mentioned with "information" about it. If you feel a game is missing or don't agree with a game being here, tell me why and I might reconsider. People that only give links to information about a game without writing the name and some info won't see it appear here if no one else gives the info.

I would like to thank Andrey82 for giving me permission to keep an unofficially confirmed list of my own and for providing the list in the above thread. If he ever wishes for me to stop providing a list here, I will.

3 minutes to Midnight -Source: post8027 post8506
Agony -Source: post8240 post8351
Amid Evil -Source: post8191
Army Men: Sarge's War -Source: post7847
Assassin's Creed 2 -Source: post8039
Assassin's Creed 3 -Source: post8039
ASYLUM -Source: forum
Atomic Heart -Source: post8871
Backbone -Source: post8974
Black Geyser: Couriers of Darkness -Source: post8321
Blood Remaster -Source: post9137
Bomber Crew -Source: post7843
Chasm-Source: post8148 (not likely a day-one release)
Civilization V -Source: post8529 post8951
Coffee Crisis -Source: post8266
Cuphead: Delicious Last Course DLC -Source: post8372
Din's Legacy -Source: post8729
Dusk -Source: post8191 post8985
Encased -Source: post8102 post8800
Farm Folks -Source: post8506
Fell Seal: Arbiter's Mark -Source: post8090
Fluffy Horde -Source: post8742
Full Metal Furies -Source: post7942
Gibbous: A Cthulhu Adventure -Source: forum
Gravity Circuit -Source: post8529
Gray Dawn -Source: post8289
Kingdom: Two Crowns -Source: post9020
Mable and the Woods -Source: post8974
Mage's Initiation -Source: post9215
MechWarrior 5: Mercenaries -Source: post7915 (Thanks WinterSnowfall)
MegaSphere -Source: post8913
Mutant Year Zero: Road to Eden -Source: post9040
My Time at Portia -Source: post8007
Nighthawks - The Vampire RPG -Source: post8868
Once Upon a Coma -Source: post7979
Realms Beyond -Source: post8503
Red Comrades 2 -Source: post8148
Revenge of the Titans -Source: post8249
Road Redemption -Source: post7803
Skyrim -Source: post8039
Sniper Elite V2 -Source: post8148
Someday You'll Return -Source: post8372
Stronghold 2 -Source: post8961
Stronghold 3 -Source: post8961
Stronghold Legends -Source: post8961
Super Hero League of Hoboken -Source: post8148 post8791
The Last Night -Source: post7993
The Myst 25th Anniversary Collection -Source: post8156
The New World -Source: post8693
The Unlikely Legend of Rusty Pup -Source: post8871
They Are Billions -Source: post6969 post7833
UnDungeon -Source: post7993

Unofficially confirmed games: 2017

911 Operator -Source: post6250
Army Men: Air Tactics -Source: post7452
Astroneer -Source: post3280 post6166
Black Annex -Source: post1280 post6166
Blasphemous -Source: post6789 post7007
Carnivores Games -Source: post6151
Codename Panzers: Cold War -Source: post3280 post6166
Constructor HD -Source: post1792 and here
Copper Dreams -Source: post6960
Cyberpunk 2077 -Source: post22 post6316
Defender's Quest 2 - Source: post159 post6166
Demons Age -Source: post3280 post6166
Door Kickers: Action Squad -Source: post7603
Dragon Fin Soup -Source: post3280 post6166
Drakensang -Source: post7452 post8863
Entymology -Source: post6356 Is that even a game?
Excubitor -Source: post3280 post6166
Forsaken Castle -Source: post6685
Grav -Source: post3280 post6166 (seems abandoned)
Has Been Heroes -Source: post6506
Hellpoint -Source post6486 post6621
High Hell -Source: post7380
Keen Dreams -Source: post7352
Kill To Collect -Source: post3280 post6166
Life Is Feudal: Your Own -Source: post3280 post6166
Medieval Engineers -Source: post3280 post6166
Northgard -Source: post6265
Paradise Lost: First Contact -Source: post6163
Pathfinder Adventures -Source: post6840
Phoenix Point -Source: post6600
Planetary Annihilation: TITANS -Source: post3280 post6166
Red Comrades Save the Galaxy: Reloaded -Source: post7041
Redeemer -Source: post6227 post6254
Rise & Shine -Source: post7288
Sacred Fire -Source: post6417 post6429
Savage Lands -Source: post3280 post6166
Senran Kagura Shinovi Versus -Source: post3280 post6166
Space Engineers -Source: post3280 post6166
Stardrive -Source: post3280 post6166
Stardrive 2 -Source: post3280 post6166
Stifled -Source: post7452
Stranded Deep -Source: post3895 post6162
Sully: A Very Serious RPG -Source: post3280 post6166
The Franz Kafka Videogame -Source: post6347
The Mandate -Source: post172 post6166 (seems abandoned)
The Neverhood -Source: post699 post6623
The Norwood Suite -Source: post7288
Town Of Light -Source: post3280 post6166
Upwards, Lonely Robot -Source: post3280 post6166
White Day: A Labyrinth Named School - Source: post7341
Wizardry 1-5 -Source: post6695
Worlds Of Magic -Source: post109 post6320 (probably won't come)
Xenonauts 2 -Source: post6173 post6282
Yonder: The Cloud Catcher Chronicles -Source: post7058
Zeno Clash -Source: post3280 post6166

Unofficially confirmed games: 2016 - 2015 - 2014 - 2013

2016

Arakion -Source: post4906
Arcadian Atlas -Source: post2642
BattleTanx -Source: post2904 post4479
Brawl -Source: post4593
Captain Quazar -Source: post2904 post4479
Crush Your Enemies -Source: post4356
Dinocide -Source: post2799
Door Kickers 2 -Source: post2952
Ghost 1.0 -Source: post3745
Hammer And Sickle -Source: post3811
Her Majesty's SPIFFING -Source: post5495
Insanely Twisted Shadow Planet -Source: post4553
Jay and Silent Bob: Chronic Blunt Punch -Source: post2740
KeeperRL -Source: post2809
Niffelheim -Source: post3280
Nightcry -Source: post2892
Project Resurgence -Source: post4279 (studio dissolved, they *might* still do the game, but I'm not following it anymore)
Reflections -Source: post4279
Rhem 1 -Source: post2638
Rhem 4 -Source: post2638
Scorn -Source: post4618
Shrouded In Sanity -Source: post4279
State Of Decay: Year One Survival Edition -Source: post4219 post5107
Subnautica -Source: post3452
The Bunker - Source: post4880
The Fall Of Lazarus -Source: post4577
The Pit -Source: post3280 (Is this the iOS game or the card game? Unsure if I should count it as released or not)
The Political Machine 2016 -Source: post3280
The Quest -Source: post2465 post2525 (Rejected)
Wasteland 3 -Source: post5469 post5607

2015

2Dark -Source: post1627
Albert & Otto (Episode 1) -Source: post1985 (Is this game completed? Are they making only poop games now?)
American McGee's Scrapland -Source: post1451
Axiom Verge -Source: post1571
Black Ice -Source: post1222
Call Of Cthulhu: The Wasted Land -Source: post2396 post2399 (Rejected, Unavailable because of licensing problems)
Cogmind -Source: post1771
Decay: The Mare -Source: post1283
Edge Of Eternity -Source: post1321
First Wonder -Source: post2039
Frontiers -Source: post1704
Garbage Day -Source: 2203
Legends of Dawn -Source: post138 post2268 (GROOT says: Avoid it! post 17 on this page) :P
Luckslinger -Source: post1758
Mugen Souls -Source: post2171
Paradise Never -Source: post1373
Psychonauts 2 -Source: post2377
Seven Dragon Saga -Source: post1399 (Cancelled)
Shakedown Hawaii -Source: post2350
Shallow Space: Insurgency -Source: 1612
Son Of Nor -Source: post1479
Stars Beyond Reach -Source: post2088
Tengami -Source: post1313
They Bleed Pixels -Source: post1684
The Consuming Shadow -Source: post1788 post2075 (Rejected)
Vertiginous Golf -Source: post1513

2014

Children Of Liberty -Source: post262
Gex 2 -Source: post1089
Gex 3 -Source: post1089 1101 (Probably not)
Gold Rush! - Source: post764
Legions Of Ashworld -Source: post32 post684 (Rejected?)
Machines At War -Source: post688 post810 (Rejected)
Manos: The Hand Of Fate -Source: post1059
Mims -Source: post1072
Shiness -Source: post541
Star Command Galaxies -Source: post1139
Ultionus A Tale Of Pretty Revenge -Source: post263 post394
Woolfe: The Red Hood Diaries -Source: post828

2013

Cryamore -Source: post138
Deathfire: Ruins of Nethermore -Source: post172 (Cancelled)
Doorways -Source: post108
Fade To Black -Source: post138
Iron Soul -Source: post30
Planetary Annihilation -Source: post138
Routine -Source: post138
Silver Symbiosis -Source: post66 (abandoned project?)
Spud's Quest -Source: post65
The Dream Machine -Source: post138
Trial By Magic -Source: post138
Two Guys SpaceVenture -Source: post138
Wreckfest (Next Car Game) -Source: post29

Episodic games / Episodic DLCs we're waiting on:

If I'm missing anything point it out.

Hiveswap -- Act: 2 -3 -4
Kentucky Route Zero -- Act: 5
The Bard's Tale Trilogy Volume: 3
The Walking Dead: The Final Season Episodes 3- 4

Latest updates:

I've added all the lists, here are some changes I've made:


Unofficially confirmed games: 2017

Games in the list that I've unboldened (?) since they seem to be abandoned:
Grav
The Mandate

-------------------------

Now to wait for developers, publishers and GOG to get back to work so we can get new information about game releases. ;) Hope for good health for everyone this year, and a special thanks again to everyone that contributes information that gets added here. This thread would not exist without your contributions. Thank you.

Latest updates:

Unofficially confirmed games

Removed Cold Waters -Source: post7738, released January 04 2018
Removed Oriental Empires -Source: post7738, released January 04 208

Still waiting on Tokyo Xanadu eX+. What a familiar feeling.

Subnautica is being released on Steam on January 23rd. I hope we see this game on gog soon.

Latest updates:

Calendar

Added Nantucket, January 18 2018
Added Treasure Adventure World, February 07 2018 -Unofficial date from the publisher's twitter-

Unofficially confirmed games

Moved Treasure Adventure World -Source: post7214 post7759 to the calendar


---------------------------------------------------------------


Sorry saw your post after sending mine. Indeed the twitter account of a designer for Subnautica is talking about the v1.0 launch, but since I haven't seen a confirmation for GOG, I'll add it in a weekly update. Maybe we'll see the game here.

New release date for Ys VIII is January 30:
https://gematsu.com/2018/01/ys-viii-pc-launches-january-30-alongside-ps4-ps-vita-localization-update

Zwei: The Arges Adventure is confirmed for a January 24 release.

https://twitter.com/XSEEDGames/status/951516812138635264

Opus Magnum have been rejected by gOg