It's by the GloriousEggroll guys, and I really liked it a lot. I would still be using it if it worked better with my laptop's hybrid Nvidia graphics setup. When I get around to swapping my desktop to linux, I'll almost certainly go with Nobara first.
FWIW, Pop!_OS is where I landed for great hybrid graphics support.
Thanks for the advice. Unfortunately, when I double click setup.exe, it opens ProtonTricks, rather than install anything. I tried running it through the terminal window directly and it looked like it installed but when I tried to run it afterwards I got errors like it couldn't find the files.
I dunno, I will probably just end up dual booting. This is EXACTLY the kind of experience that kept me from linux for the last couple decades. I am positive with enough effort I could get it working. I just don't want to put in that kind of effort; I don't want a new hobby.
Fortunately, when I'm not trying to install a 20-year old game made for the wrong operating system, things DO just work. :-D