Who hasn't ;-)

Those guys over in dem English-speaking countries.

Also, I'd point out that the user's privacy is not at all GOG's highest priority. And if anyone cares about online tracking and the like, then you're not gonna like galaxy.

Web browsers give you the opportunity to block google analytics and such, but galaxy (which uses the same webpages) does not.

A big boo.

Are you sure? I often get the impression native speakers are a lot more careless about their use of language...

I stumbled over <span class="podkreslenie">this</span>.
Maybe ot`s helpfull.

The games themselves keep track of achievements and when they are met and keep track of that locally I believe somewhere under C:\ProgramData\gog.com\.... somewhere. I believe that if and when you connect to Galaxy via the client, it can register your achievements with the Galaxy servers. This is intended to be an optional feature however, and the client has a placeholder for it in the "Settings" configuration screen under "Features (Coming soon)" named "Achievements". Presumably if one turns that option off then it wont keep track of achievements for games on GOG's servers. Since the client is in development/beta right now however they haven't gotten that part implemented yet as none of those feature toggles are active yet. Even the "In-Game Overlay" which is switchable is not actually hooked up to anything yet so it isn't functional.

Hopefully they will enable the overlay and make the various options functional which have not yet been implemented but are on the TODO list. They will no doubt likely add a lot more options that have been discussed that do not yet show up on the configuration screen as well.

While the client is deeply in development right now and a lot of features and functionality are not yet implemented, they're on their TODO list, but if any such features are crucial for anyone then it is probably a good idea to avoid testing the client at this point until they have time to fully implement everything and make an non-beta official stable public release. At that time, all of these things should presumably be in place.

Personally I'm looking forward to the "In-Game Overlay" button doing something useful soon. :)

This is a BIG THEORY, but what if someone else had used the same account with the game playing it on Galaxy? But then I guess I can poke that theory, because you said there were no achievements unlocked.
don't forget; there, they're and their. As well as wear, and where.

I would imagine one of two things:

Witcher uses a CDPR account at some point and the game itself uploaded this info. Your CDPR and GOG accounts are now one and the same.

Or #2: Witcher 3 came with GOG Galaxy parts, similar to AvP 2000 and Witcher Board Game. So it was updating your account like you had Galaxy, but you didn't know it.

Maybe could be a good idea to add something similar to "Track your already connected devices" like Facebook does (and I think Steam as well)

If you have only one HD in your computer then you swapped your whole disc space, that means the info about your game progress cannot be stored locally, it must have been stored online.

Since you did not authentificate during playing Witcher 3 (did you?), either your initial download was marked (should be easy to detect with a hash comparison) or Witcher 3 generated a unique id from your hardware and used this to authentificate you.

Wasn't this topic done/question answered?

You forgot: were.
Like in: "Were has this thread gone?". .-)

That's actually 'where'.
Were is different again :)

But I did forget we're, as in "we're going somewhere with this thread".

Yes, but since when do people bother to read the entire thread before posting? This... is... THE INTERNEEEEEEEEET!!!!!
Nothing beats its vs it's. Now that really grinds my gears...

Ah, damn, I forgot the "h"! I was too hasty.
Was and were, which and witch, there are so many possibillities (I guess I wrote that wrong) to make mistakes in the english language.