which game? An exclusive?

Star Control II was on other platforms, but was great on 3DO, http://sc2.sourceforge.net/ is free now and a deep game. Like 2D Mass Effect I thought. (Star Control II: The Ur-Quan Masters)

I also enjoyed Return Fire and PoliceNauts which are both available on other platforms also. Wing Commander III maybe?

road and track Need for Speed, had other ports, but 3do was arguably the best version.