If I do opt for the Steam OS will my GOG Galaxy run on it or will I just have to launch the games directly? Most of the titles I play (other than the Halo games and Forbidden West) are using the Galaxy app.

What GOG support will there be from SteamOS, if any?

You’ll be able to access those games through the Heroic Launcher, it should be able to handle any GOG games you have just as easily as Steam will handle Steam games.

I have not used it myself but you should be able to run typical linux desktop software with steamos. That being said, I don’t think there’s gog galaxy for linux. You can use HeroicLauncher for GOG (and epic and prime gaming) instead.

I think this post provides a pretty good high level introduction: https://www.gamingonlinux.com/guides/view/how-to-install-extra-software-apps-and-games-on-steamos-and-steam-deck/

Alternatively, you could try a gaming focused Linux distribution like bazzite (based on fedora/ublue) which comes with a lot of gaming related stuff preinstalled or easy to install. The base system is mostly read only though and if you need the latest version of some software that’s not on flathub, it can be a little limiting.

cachyos (based on arch) is a good alternative if you would like to be able to get your hands dirty tweaking your system or want more freedom wrt installing software.

In any case, you should check https://www.protondb.com/ if your games are supported.

Some games with certain anti cheat software can not be run (e.g. anything using vanguard, riot’s anti cheat).

Do note that if you’re in the EU (or can convince Windows/Microsoft that you are, I assume) you should get Windows 10 patches for another year without doing anything.

When I saw the post and writeup, I knew it would be Linux (or Bazzite).

SteamOS is not available as a general install media for your PC. SteamOS from Valve is based on Archlinux. There are many different base Linux systems other operating systems / distros use them and build a new system around it (just like what Valve did with Archlinux into SteamOS). In general, SteamOS itself does not integrate GOG or any other launcher out of the box. You would need manual installation in desktop mode (normal PC mode) and add them into the Steam as non Steam game. Its just like on your regular PC. But as said, that does not matter, because SteamOS itself is not available for general PC.

But there is Linux distribution that aims to fill that gap, called Bazzite: https://bazzite.gg/ Its base system is different from SteamOS, but it is gaming first oriented. It’s quite popular. And integrates other stores as well:

Own games outside of Steam? Lutris (Pre-installed) and other launchers can not only run games from most game stores, but cleanly integrate them into Steam Gaming Mode, including: Xbox Game Pass (via battle.net), EA App, Epic Games Store, GOG.com, itch.io, Rockstar Games Launcher, Ubisoft Connect, your dad’s old CDs, and more!

There was also one called HoloISO, which was much much closer to SteamOS. But that one did not see any development since over a year, so I would rule that out.

Firstly if you’re looking to upgrade your system and switch to Linux, I would recommend switching to team Red. For a variety of reasons really but generally they are a better value and also will just work better with Linux.

GOG games can be run on SteamOS and SteamOS-like distros through Heroic and Lutris. Though YMMV. You’re going to have a much better time playing games on Steam.

Valve is not going to give you support for GOG but Linux is a community-driven project and probably the vast majority of Linux users are going to want to run games from other stores.