So I am very new to GOG, I just got the Ultimate edition of Cyberpunk yesterday and I went to install it and this obviously went to then download Galaxy first before installing the game with the client. As it was downloading I noticed in the extras that the offline installation files in the extras tab for the game was around 105gb (not including the dlc) compared to downloading the game with the client which was only around 80gbs.

I looked online and I get that with Galaxy you can only play the game with internet access rather than whenever if you use the offline installation which I get, but I am very confused with how to proceed from here. Is it better to do the offline installation from the GOG store page for the game, or on the Galaxy page for the game? And from there how do you sort the installed files, like on the store page there are 28 separate files to download, once they're all downloaded are they extracted to one file, or something else?

Most of what I have seen online is people just saying, hit download like there is only one button for it, or other people talking about how Galaxy is terrible and to avoid it at all costs.

Edit: Additionally just to check, if I am just installing every file from the store page, do I also download every single patch, or just the most recent patches?

You don't download any patches, just the latest installer (all parts).

As for GoG Galaxy, to each their own. I hate every kind of game launcher, it's just an extra step before accessing the game that to me offers zero benefits.

As for the installers, you need to download all the 28 parts (make sure they are all located in the same folder when installing the game). Those are all the offline game installation files for the main game, already at the latest patch. No need to download any of the patches.

You also need to download the 11 files for the Phantom Liberty expansion, and run the installer for it too.

You run the installer by opening "part 1" (the small .exe), and choose your language and the install location. Let the installer do its thing, and then you can start the game from the created icon on the desktop.

And that is it.