Could somebody explain more clearly the difference between the two? I get that the gog galaxy installer comes with galaxy bundled into, but does that version forcefully install galaxy as well or, does the installer still let you choose between installing galaxy or not?

Also, how is this reflected with backup downloaded from galaxy? which version get downloaded?

Thanks to anyone willing to answer my questions :) .

Thanks to both of you for answering my questions, I really appreciate it :) .

@Thiev Yes I just did realize the "classic installer" by looking inside "more", so I made this post right after.
I didn't think that galaxy would download by default the classic installer, that's good to hear :).

Thanks again to both of you :) .

As of 2020 I struggle to find this option. Is it renamed?

Classic installers are now called "offline backup game installers". You will need to click the drop-down section to display the links, if it's the first time you download them. See attached.

And just to note, for the last few months at least, the difference between offline and galaxy installers is pretty small. Offline installers come with galaxy components “required” by the game now, I.e you cannot run them with galaxy.dll for instance. The offline don’t contain the full galaxy though.

get offline always

Could you please clarify what you mean with "you cannot run them with galaxy.dll"?

Bbtw I've also read somewhere else that galaxy installers require an internet connection in order to properly install games, which well, would definitely be a no no for me (not sure if it's true though).

https://www.gog.com/forum/general/gog_galaxy_required_in_certain_games
Certain components of galaxy have now been built into the requirements of games, including redoing old games. For instance you can no longer run the latest version of Dungeon Keeper, without having certain files like galaxy.dll.
This is an additional requirement which was never there before. And it is also increasing in both features and size of installer. So first was the dll to allow “achievements”, then came online saves, next will be multiplayer components I would imagine, and then in a year or so you will need nocd patches to be able to run the products.

So no, very little difference between the two now.

I've asked someone who bought Dungeon Keeper Gold. He installed the latest version 10.1_(28184) using the offline installer. After the installation he couldn't find a file "galaxy.dll" on his entire system. He checked the mentioned "game.gog" file in the linked thread. This file has nothing to do with Galaxy. You can see the purpose of this file by looking at the file "game.ins". It reveals that "game.gog" is a CD binary.

"redoing old games"? You can't add a galaxy.dll dependency or any other new dependency to old games without having the source code to compile a new version. The cloud saves feature was added to DOSBox. Is "galaxy.dll" necessary to run DOSBox? I haven't found anything here in the source code. This would also conflict with the GPLv2.

I don't know about Dungeon Keeper specifically but I find the galaxy.dll file in the installation folder of basically every game I've gotten nowadays. I do not buy the logic that the "galaxy.dll" file has "nothing to do with Galaxy." It's right there in the name, lol.

As far as I am aware it is in most now. If you look at the change logs they have been adding “achievements” to each game, old and new for some time, which is where the galaxy.dll mainly comes in. The more recent update has been cloud saves, which updated that file and added some folders and such like.
It’s all to do with galaxy as it all only functions when galaxy, the UI, is installed and links up. So the only effective difference is that the UI is not bundled with the offline installer. They have confirmed as much with a ticket in that they cannot provide installers without these components, even if they were able to before, blanket policy.

Yes, didn’t say that galaxy.dll was in dungeon keeper. Game.gog is an unusual one, I had assumed it was to do with the cloud saves as there are folders for it now. But your right it is just a Cd image. Which begs the question why that has increased in size. Again the change log only indicates that cloud saves have been added.
A better example might be Titan quest. It has two galaxy.dll files in THQNOnline/gog, and also some discord dll as well. The game will not start without these. You can replicate by changing the folder name.

Certainly a decent change log would help, as would being able to choose which version to download. However this vague and rather sneaky attempt comes not too far after the previous galaxy debacle of including galaxy with all installers, for which I still have those things backed up!

Edit. So a comparison of the two dungeon keeper installs shows that it’s an update (or lack of compression) in the sound folder of that image, and the subtitles. There is still a folder, a script, some ink files and such like different, but that seems fine.