8BitBoy
https://www.gog.com/wishlist/games/8bitboy
Question: "BTW, is the game Steam exclusive or have you considered selling it on Gog.com as well?"
AwesomeBlade: "I tried to get it on GOG, but they rejected it."
https://steamcommunity.com/app/296910/discussions/0/522730701623587660/

Siralim
https://www.gog.com/wishlist/games/siralim
Question: "Any plans to release this on GOG.com?"
Thylacine Studios: "We already tried, but they rejected the game."
https://steamcommunity.com/app/362090/discussions/0/368542844488191806/

Siralim 2
https://www.gog.com/wishlist/games/siralim_2
Question: "Any plans for GOG release, or DRM free?"
Thylacine Studios: "The game is DRM free despite being on Steam. DRM is actually optional on Steam - I personally didn't even know that until recently :) We were rejected by GOG for being "too niche"."
https://www.reddit.com/r/roguelikes/comments/33pgt5/siralim_a_creaturetaming_roguelike_roguelite_is/cqnm7fq/

Siralim 3
https://www.gog.com/wishlist/games/siralim_3
Question: " Siralim games on gog.com? it would be really awesome if i also could buy this games on gog.com :tinder:"
Thylacine Studios: "I've tried, but they always reject it and say that the production value is too low. :("
https://steamcommunity.com/app/841770/discussions/0/1694922526903049100/

That's it! This is simply unacceptable, GOG rejecting games from their store!

I hereby solemnly and royally vow to boycott ANY game that GOG has rejected! I will never buy them, at least from GOG!

That'll teach GOG not to reject games!

This will be funny if only the situation weren't so bad. Is GOG really this screwed up? Can I apply to vet the games for GOG instead?

The dev of The Fall Part 2: Unbound, which actually made it on GOG, had a bit of a hiccup initially: "Yeah! We got lucky. GOG actually rejected us when we applied through their automated form. Thankfully someone internally noticed that we hadn't been reached out to and got on it."
https://steamcommunity.com/app/510490/discussions/0/1318835718943880896/

It makes you wonder how many others may have fallen through the automated form cracks.

Nyu Media circa 2014: "I think a bigger factor would be that GOG haven't ever accepted any of the games we've submitted to them. We've had 3 rejections from them so far, all basically along the lines of: 'We’ve taken a look at your games, there are some interesting looking titles there! Unfortunately, however, we feel that the games would not be a good fit for GOG as arcade style games, such as yours, generally do not perform well for us.'"

https://www.gog.com/wishlist/games/alltynex_second
https://www.gog.com/wishlist/games/armed_seven
https://www.gog.com/wishlist/games/cherry_tree_high_comedy_club
https://www.gog.com/wishlist/games/cherry_tree_high_i_my_girls
https://www.gog.com/wishlist/games/croixleur_sigma
https://www.gog.com/wishlist/games/ether_vapor_remaster
https://www.gog.com/wishlist/games/exceed_gun_bullet_children
https://www.gog.com/wishlist/games/exceed_2nd_vampire_rex
https://www.gog.com/wishlist/games/exceed_3rd_jade_penetrate_black_package
https://www.gog.com/wishlist/games/fairy_bloom_freesia
https://www.gog.com/wishlist/games/gigantic_army
https://www.gog.com/wishlist/games/kamui_siter_skain
https://www.gog.com/wishlist/games/reflex
https://www.gog.com/wishlist/games/the_sacred_tears_true
https://www.gog.com/wishlist/games/satazius
https://www.gog.com/wishlist/games/steel_strider
https://www.gog.com/wishlist/games/supercharged_robot_vulkaiser
https://www.gog.com/wishlist/games/wolflame
https://www.gog.com/wishlist/games/yatagarasu_attack_on_cataclysm
https://www.gog.com/wishlist/games/zangeki_warp

Zigfrak
https://www.gog.com/wishlist/games/zigfrak
The developer tweeted: "business implies money changing hands, though. would love to be listed on GoG, but they passed on zig after evaluating a beta :-("
https://twitter.com/zigfrak/status/342490853492789249

Wings Of Vi
https://www.gog.com/wishlist/games/wings_of_vi
Dev Grynsoft tweeted: "Wings of Vi is already DRM free on steam. Tried contacting gog a long time ago but never got anything set up."

The Sacred Tears True
Satazius
Shadowgate (MacVenture Series)
Shmups Skill Test
Siralim
Siralim 2
Siralim 3
Sleepwalker
Snakebird
Space Invaders Extreme
Speedy Eggbert (a.k.a. Speedy Blupi)
Speedy Eggbert 2 (a.k.a. Speedy Blupi 2)
Spiritual Warfare
The St. Christopher's School Lockdown
Steel Strider
Subsurface Circular
Super 3-D Noah's Ark
Superbrothers: Sword And Sworcery EP
Supercharged Robot Vulkaiser
They Bleed Pixels
Thomas Was Alone
Time Gate: Knight's Chase
Tokyo Dark
Traum
Trizeal Remix
Tunnel B1
The Uncertain: Episode 1 - The Last Quiet Day
The Uncertain: Episode 2 - Light At The End
The Uninvited (MacVenture Series)
Vigilantes
Volume
Warbanners
Where Time Stood Still
Wings Of Vi
Wizorb
Wolflame
Xiizeal
Yatagarasu: Attack On Cataclysm
Zangeki Warp
Zigfrak

Games whose developers/publishers aren't interested in releasing on GOG:

Hidden Folks

Duke Grabowski, Mighty Swashbuckler!

Source: Kickstarter for Duke Grabowski

"DRM-free. This is a big issue, we know it. Unfortunately, it seems like we can only distribute the game on Steam, which has DRM. This decision was made by our publisher. We hope we can set up something later with GOG.com or Humble Bundle, but we can't promise it."

http://www.kickstarter.com/projects/venture-moon/duke-grabowski-mighty-swashbuckler-point-and-click/posts/1677589


The game has after that post appeared on Humble Bundle, but not on GOG, so whether that's their publisher's or GOG's decision can only be guessed.

Umm, no, because you are not running their business. You might keep selecting games which you think are nice but which sell very poorly on GOG, for whatever reason (like they've already been in Humble Bundle, or they lack features from the Steam version, or the developer abandons the game on GOG right away etc.).

Releasing games on GOG does cause extra work and extra expenses to GOG too, hence it makes sense they select only games they believe in. You have no money invested on GOG so you wouldn't be penalized for making wrong choices from GOG's point of view.

I sometimes keep checking some of the games that GOG has allegedly rejected, and very rarely I keep getting the feeling GOG definitely should have gotten the game to GOG. Maybe that one finger punch thingie since some people have praised it, but maybe GOG doesn't feel it would sell that much on GOG anymore.

Plus, we don't know what are all the details on rejecting the games, like maybe the developer wanted to slap some DRM on top of it etc.

Games by Castle Pixel studio

They've revealed a while ago in a tweet that their first game, Rex Rocket

https://store.steampowered.com/app/288020/Rex_Rocket/

has been declined by GOG overlords.

As a consequence, they didn't even bother submitting their second game, Blossom Tales: The Sleeping King

https://store.steampowered.com/app/446810/Blossom_Tales_The_Sleeping_King/

I've contacted the studio responsible for making these games several times, but they never answered.

Unfortunately GOG overlords are truly morons when it comes to indie games.