Je sais un petit peu de français seulment mais je peux essayer de vous aider aprés je dors.

La page suivante devrait te donner accès aux jeux que tu as achetés, des liens de téléchargement s’y trouvent :
https://www.gog.com/account

FYI: pre-built binaries of OpenJK don't work in Debian testing.

Debian has packages that work in experimental: https://packages.debian.org/search?searchon=names&keywords=openjk

That reminds me... Is there a list of games sold on GOG that are supported by open source engines?

Some engines are listed here: https://www.gamingonlinux.com/wiki/Open_Source_Game_Engines_List

But that list doesn't specifically focus on GOG. Feel free to expand and correct it if you know more.

I need to upgrade my distro and am now about to flip a coin, or just ask here, whether to choose 32bit or 64bit. I know the route of 32 bit is coming to an end soon but will do a fresh install when that day comes anyway. I have 3GB of RAM and am not going to add a fourth to a ten year old computer.

Opinions? Let the snowball fight commence! No rocks! No chunks of ice! No napalm!

I can’t see any reason today to stick to a 32-bit OS if your hardware can run a 64-bit one.

Before upgrading, it could be a good idea to check how easy/difficult it is to install 32-bit software on the 64-bit version of your distribution, as there is still a lot of commercial games not providing a 64-bit build.

Don't use 32-bit, unless your hardware isn't 64-bit capable (and today all non mobile CPUs are 64-bit capable). That should work well as a criterion.

The computer is 64bit capable and what is now installed is 64bit. Since I posted my question my mind has leaned more and more towards sticking to 64bit and what the kind people here have said only makes me bang the gavel down on it. RATS! Barely missed hitting the laptop there.
Thanks for your input!

I's been months since I last logged in, now I can't access the store or library anymore, none of the games show up, there are no download links. there's just a spinning button and blank page, account button is missing from top banner, gog.com/##openlogin doesn't work anymore so I used login.gog.com/login but there's zero indication on whether or not I'm actually logged in to the site like it used to be before on top banner.
Website is unusable here (linux, firefox 52.1.0)

Try cleaning up all GOG cookies. Also, GOG sometimes behaves weirdly with some VPNs.

Use Firefox Console / Network monitor then to figure out what's going on.

Nothing critical, although api.rollbar.com notes '429 Too many requests' and times out.
And some error on screenshot.

I've identified the source of the problem, seems that the menu navigation requires dom.storage.enabled > true
The site fails to open the hover menu or display the "sign in" button if this feature is disabled, which shouldn't be the case.
For example reuters website has a hover menu that just works regardless of this browser preference.