90's Linux gaming was a lot of Freeciv, Doom, Quake 3, and Tux Racer.
Wine really didn't work for shit for AT LEAST another decade, and even then, didn't really really work for a further decade after that. It took a very very long time for Wine to get to where it is now with Proton and playing basically everything that doesn't need a rootkit to run.
As for finding Linux games, I could just go to Microcenter. They had a whole shelf full of Linux software ranging from distros, to games, to commercial office suites, to just random shit that looked like it was boxed up in some guy's garage and contained just... stuff. I miss being able to buy software in big shiny boxes, though :(