All good points. I guess when it comes to the distinction between devs and publishers, all we can do is go one of two ways:
- Punishing a new developer by labelling their publisher "unreliable", even if the dev still has everything to prove.
- Allowing newcomers to run into problems with new developers published by unreliable publishers because we have no data on the developers themselves and we don't judge them based on their publisher.

BTW: Can anyone give a good example for a highly reliable dev combined with a highly unreliable publisher?

And just to make a suggestion for the discussion: Maybe it would make sense to only consider developers and then just have a few rules which are draconian but easy to understand for newcomers to GOG and don't require the people collating the list to count every single game of every developer against the number of issues they have. Something like:
1. Any developer selling a game on GOG that is at least x months out-of-date compared to Steam is considered "unreliable".
2. Any developer selling a game on GOG that is missing a gameplay-relevant DLC for at least x months after its release on Steam is considered "unreliable".
3. Developers can lose their "unreliable" status by fixing all issues derived from points 1 and 2.
4. Developers who can't/don't update their games as per 1 or 2 can be deemed "rehabilitated" if they publish at least two more games on GOG which have received at least one update each and which do not themselves trigger rules 1 and 2.
5. Developers who trigger 1 or 2 while considered "rehabilitated" as per 4 will be considered "unreliable" and lose the ability to become "rehabilitated" again.

It doesn't have to be that the publisher is blocking the developer. It might simply be a division of labour.

For example, I contacted the developer of "Fell Seal" a year or so ago to report a GOG-specific issue and they told me that they were passing the information to the publisher, because the developer was responsible for steam updates and the publisher for GOG updates. In my case, the issue was fixed, presumably by the publsher, some time later, but I assume there are better and worse publishers out there.

It highly depends of what you consider highly unreliable since most fall in the middle but yes there is one publisher above all else which should be avoided at any cost, tinyBuild and i have previously considered Icepick Lodge very reliable until checking up now years later to see Pathologic 2 lacking updates since 2019.

Devolver i would consider atleast unreliable but Flying Wild Hogs and devs of The Messenger are on point for example.

Team 17 is very unreliable overall and Blasphemous despite not having Linux gets updates on point it seems.

I don't buy tinyBuild or Team 17 published games because these companies are atrocious and would do us a favor if they left GOG so i can't speak for all their games.

And for mrkgnao, thanks for the explanation.

Thanks for the examples, I think I've heard other people talk about Devolver being terrible on GOG as well - maybe another candidate for the blacklist :D

That being said, I think Pathologic 2 hasn't received any updates since 2019 on Steam either and I think the studio has had financial troubles - no idea if they even exist still.

But wasn't tiunyBuild redeemed? I remember that there was a time when several games weren't updated but then they suddenly turned around and delivered all missing updates. I did not realize that they fell back into old patterns.

It says unofficial localization updates on Steam but don't list them as supported languages so i can't say for certain but perhaps someone who owns the game on both platforms can say.

Regardless the takeaway here is do not buy tinyBuild or Team 17 games at any cost and research the developers with Devolver.
Some games are equal to Steam but not all and the thing is tinyBuild can't redeem themselves after their history here. I will not be fooled with their promises so it has to go years with clean records to get me back.

As far as I can tell, these unofficial translations are fan-made. So the devs have posted notifications to tell their fans that unofficial translations are available, but these are not official updates.

As far as I can tell, these files aren't even solely available on Steam, they're hosted on third-party sites like Google Drive and such. Maybe you can even put them into a GOG installation of Pathologic 2.

Thanks, that is such a relief i tell you. I thought tinyBuild had managed to corrupt even Icepick Lodge so i'm happy that wasn't the case and that they are still around hopefully.

Hmmm ... that's your decision. Imo everybody deserves a second chance. Could you tell me which tinyBuild games are still not up to date?

Here is my short conversation with tinyBuild back then. Everything sounds as if they really wanted to make things right. Glad to hear that I was not completely wrong about that. Yes, they messed up big time but at least they also tried to fix things:

https://drive.google.com/drive/folders/17CAe_HQWF7aB3aA7qxNcJtqnI0DauMxZ?usp=sharing

Today's release Flynn: Son of Crimson is missing the paid soundtrack DLC. The soundtrack is available DRM-free on the composer's Bandcamp page, though that version lacks a two-minute song named "Kickstarter Trailer" compared to Steam.

A bit of context: The game is released by Humble Games. I've had a look at their releases on GOG as well as the list of issues and it looks like no game published by Humble Games on GOG has ever had its soundtrack released here. And then I found this post by the dev of Crying Suns explaining that they were trying to get the soundtrack here, but their publishing partner doesn't want to release it on GOG. Now, it's unclear to me whether "publishing partner" means Humble Games, since the previous post says "publishing partner for the music", so it might be a problem with the composer or whatever. But I thought I'd bring it up since this is an example of a dev trying to get all their stuff on GOG and being blocked by someone on the publishing side of business.

A Hat in Time just received the latest fixes and improvements from the Steam version. That doesn't undo the whole modding and multiplayer thing, but it does mean the game itself is now up-to-date and that issue can be removed from the list.

EDIT: Maybe we should also consider adding Quake to the list at this point - we got the confirmation that the GOG build of the enhanced version was being finalized and will be available to GOG customers about a month ago now and nothing has happened.

EDIT2: Eastward released without the purchasable soundtrack DLC today. You can get that soundtrack DRM-free on the composer's Bandcamp page. Looks like that version even includes an additional song compared to the Steam version.

EDIT3: According to people from China and Taiwan in the release thread for Eastward, that game is also region locked on GOG in China and Taiwan. Not the case for Steam, apparently.

Not adding to the current conversation, just want to thank everyone maintaining this list. It's extremely relevant information for potential customers.

I believe that GOG actually has a 48-hour parity update clause in their agreements with developers and publishers, but obviously enforcement is difficult when you lack the leverage of Valve, Epic, Sony or Microsoft. Most will simply tell GOG to get knotted and remove themselves from the platform.

Basically, you need something that will stroke the publishers or dev's egos (or wallets) if you want to guarantee parity updates. Something like an increased cut of sales or landing page exposure (in the line of how Steam shows games that were recently updated with new modes, etc).

SYNTHETIK: Legion Rising is currently missing two paid DLCs. It's not obviously noticeable, as getting them involves purchasing the DLCs for the free-to-play spin-off, Arena:
- SYNTHETIK: Arena Premium Upgrade
- SYNTHETIK: Arena Supporter Pack

Purchasing these will unlock some features/drops in Legion Rising, which are even shown in the GOG build, just disabled. There was some talk about it coming to GOG, but it never seem to have been realized.

Funnily enough, the game also seems to treat Steam users as second class in a way, as one of the items, the Acid Mine, is supposedly exclusive to the GOG version.