I'm not sure it qualifies, as it was open sourced posthumously, but Warzone 2100 https://wz2100.net/ - was so original I've never played any other game with similar mechanics.
> Warzone 2100 was originally developed by Pumpkin Studios and published by Eidos Interactive. In 1999, it was released commercially for Microsoft Windows and Sony PlayStation. Pumpkin Studios ended their support for Warzone 2100 on January 5, 2000.
Huh, if it was designed with a PlayStation controller in mind it might actually control nicely on a Steam Deack. And it has Linux support!
