So far the oldest game binary I have launched has been the original Linux port of Doom. This brought me back to 1994, both the year I was born and the year that the Linux kernel reached its milestone 1.0 release. Browsing an old SunSITE archive I came across the jetpack-linux.tar.z tarball, which contained an unusual X11 game built and packaged in June 1993.
https://www.gamingonlinux.com/2025/03/building-a-retro-linux-gaming-computer-part-47-before-i-was-born/