One I've been meaning to point out for a while now is Zoom Platform. A games store that tries to appeal to "Generation X" with both new and classic games, DRM-free and they're continuing to build up their Linux support.
They don't have a whole lot available for Linux Native fans right now, with 26 titles currently tagged as supported including Sensible World of Soccer 96-97, Duke Nukem 3D: Atomic Edition, Judge Dredd and more but they're continuing to build it up.
Recently they updated a bunch of Duke Nukem titles that use DOSBox, to work better with both the DOSBox and DOSBox-X flatpaks and over the last few months they've added more titles. Just recently, they also added Linux support for Oddworld: New 'n' Tasty, noting on Twitter a goal of theirs is to "support Linux as much as we can".
It's interesting to see a store that tries to appeal to the slightly older generation of gamers. As much as GOG tried to in the past, they've long since moved their focus much more onto modern releases. So perhaps some older readers might want to keep an eye on Zoom Platform.