Too bad if you're interested in playing Age Of Empires 2 and older titles like Medieval Total War...

There are some concern about graphics performance as well, it seems most titles are not tuned for Linux. Do you have the same graphic performance under linux?

Linux can play pretty much anything under Proton now. And older games tend to work better than on Windows because Proton runs the actual code instead of trying to force it through the current windows OS that is 10 versions on and doesn't have any of the APIs anymore. A lot of old windows games don't even run on windows anymore.

Thanks, I might need to try that, does Proton require SteamOS or I could use any linux flavor I like?

There's no particular distro preference. If you can install Steam on it, Proton is also likely to work. Steam's SteamOS is Arch based (btw), used to be Debian based. Steam games used to target Ubuntu, I can't find the sources for this, but I remember seeing it as a target. LTS versions usually.

I personally had good experience with either Mint Cinnamon, Debian (with KDE), Fedora and Manjaro, so it's pick your poison, really. For support reasons, I suggest a popular distro.

You can use any distro you like. I'm using OpenSUSE Tumbleweed and have basically the same experience as most people on ProtonDB. The thing to remember is that to use Proton for games that Valve hasn't verified, you have to go into your Steam settings and under Steam Play check "Enable Steam Play for all other titles".

I have noticed that some games work better or worse under different versions of Proton, though.

Just install the steam client and enable compatibility. I always set it to forced experimental to use the most up to date version of proton

As long as it can run Steam. Steam on Linux has Proton built in.

What's the problem with AoE II? It's rated gold on https://www.protondb.com/app/221380 and runs fine for me under Proton.

There's a definitive edition now that everyone plays and it also happens to be from literally Microsoft themselves..

And that definitive edition is listed as gold on ProtonDB.

Well now you guys have given me no excuse, RIP Windows on my gaming desktop 2019-2022.

AoE runs fantastic. Controls are an obvious issue but you can connect up a keyboard and mouse