I am something of a fan of artificial life / evolution simulation games. What games of this genre are available for Ubuntu?
Preferably it should be something fairly complex yet user-friendly; note that I'm not talking about Game of Life clones (too rigid for my taste).
Critterding is a 3D physics and neural network alife simulator with a package available for Ubuntu.
Evolve4.0 isn't a linux program but runs happily through wine! (install through winefile)
if you go to Ubuntu Software Center (the little shopping bag icon, or search for "Software" in the dash), you can search by category or keyword. Categories -> Games -> Simulation turns up a few but the pickings are slim. Many that are included in the software center are pretty weak but LinCity NG is pretty good.
Here is a list of some others that you can download. I haven't tried any of them but some look pretty slick.
My favorite is this java program, Biogenesis: http://biogenesis.sourceforge.net
It's a reimplementation of an windows app, called Primordial Life. It's very fun to watch.
The only other lead I found was this list, which looks about 10 years old: http://www.cs.iastate.edu/~baojie/acad/reference/forge/alife.htm
Forgive the lateness of my answer, I only found your question after searching for the same thing myself today.
