If you’re interested in 4X games at all Sid Meier’s Alpha Centauri is only $1.49. It absolutely holds up and to this day probably still has the best story of any 4X game.
It also works great on Steamdeck with a couple of easy tweaks. Unfortunately the instructions for those tweaks are currently in Reddit blackout shutdown limbo so I can’t copy them here, but when the blackout ends you can Find The Instructions Here.
I’ve played the GOG version of Witcher 3, Alpha Centauri, and Wasteland 2 on my Steamdeck. All worked great, though Alpha Centauri needs some easy tweaks you can find here when the Reddit blackout is over.