Introversion, the UK indie game developer of Darwinia and Uplink, just released the public beta of the Linux port of their global thermonuclear warfare sim, Defcon. The names come straight from Introversion’s forums here.
You can get the demo from links in this post.
I tried the demo on my Ubuntu 6.10 desktop. Runs without a hitch and below is the proof:
Defcon 1.4.2 Beta 2 menu screen: