You said three releases.

1. Das Geisterschiff / The Ghost Ship
2. Der Geisterjaeger / The Ghost Hunter

I think you skipped Der Geisterturm / The Ghost Tower in the original post.

And this, my friends, is what we call a formal fallacy...

Let's see: so, these three games have collected 649, 919 and 1065 votes. Ok.
Now you say, these wishlist votes are the reason, why these games got released here.

But - what about games that got released here, without having a single wishlist entry?
Or what about games that have collected up to 61.000 votes with their wishlist entries, and yet don't get released?

That's where your argument falls flat on its nose.

The (number of) votes on the wishlist mean(s) nothing at all, if GOG is either unable to find the current rights holder, or if one of the parties involved (GOG and/or any number of different rights holders) don't want a game to be released here.

I didn't say this was generally the case (otherwise we should have gotten things like the aforementioned UnReal World or Realms of Antiquity or other titles with more than 1000 votes long ago) but another one of the many previously ignored or rejected titles where continuous accumulation of votes very likely has contributed to the corresponding title (or titles) to finally being added to the catalogue.
Surt R/Graverobber Foundation also being more pro-active about it and pointing out the amount of votes to GoG (on Twitter, I believe) may have helped as well. Or at least I like to think it has.

I'm sure most are well aware that in these cases it's often a completely different story why they're not available on GoG already and, for all we know no amount of votes is likely going to change that in the foreseeable future.
Obviously it doesn't keep people from continuing to vote on the corresponding wishlist entries anyway.

Gotta be honest, that first game 'The Ghost Ship' reminds me a lot of the old Nintendo 'Virtual Boy' from the 90s. Got to try one of those once and the red coloration gave me intense eye strain.

Good thing, the game on GOG have more than the steam's ones, as of today.
(Steam 's one are very basic, while the GOG's one have at least cloud saves).

Yeah, unfortunately the red color seems like a poor choice. I assume there's no option to change the color, but it would have been nice.

All three are covered in the news post. (Sometimes the auto-converted[?] forum-post version of an actual news post misses some stuff.)

Hi everyone, thanks for checking out the Der Geist series.

If you're wondering which game you should start with, I usually suggest playing them in chronological order, but the first game tends to scare people away due to its hellish visuals and intimidating nature, so I came up with a short guide to get you started.

Each game in the series aims to create the feeling of piloting a hunk of junk on a suicide mission in a dying world. The first one is somewhat simplistic and unforgiving, but subsequent games took the ideas from the original and built upon them, adding new mechanics and making existing mechanics more nuanced.

In short:

1. Das Geisterschiff -- the first game, a high focus on exploration and survival through suicide missions, but lacking in terms of mechanical complexity. Get this one if you want an atmospheric adventure-style experience.

2. Der Geisterturm -- a spin-off to DGS, has higher mechanical complexity and focuses on combat, but the scenario itself is very linear. Get this one if you want tactical turn-based battles where you're constantly outnumbered and have to use your wits to survive.

3. Der Geisterjäger -- a sequel to DGT, focuses on both combat and exploration. It's the biggest and the most advanced game in the series. Get this one if you want all of the above but with more player agency.