Updated: 12/29/2005
Game-Sim
AI Planet
Simulates a planet with interacting creatures, birds, robots, fish, hawks, crabs, sharks, grazers, Trex, turtles, various fruit trees and grass. Also features currents, wind, lightning, growing seeds. Add land, rivers, moons and let it run. Requires P3 800MHZ, 256MB RAM, Win 98+, OpenGL 3d graphics card (preferable Geforce2 or better). [Report a dead link]
http://aiplanet.sourceforge.net/

Bitozoa
Life simulation with plants, herbivores, and carnivores. [Report a dead link]
http://www.bpp.com.pl/bitozoa2/bitozoa2.html

Bloboids
Growing 3d life with CA and implicit growth. Breed interesting 3d multicolor shapes. [Report a dead link]
http://www.ifi.unizh.ch/ailab/people/thomas/
[Screenshot]

CAFun
Cellular automata fun. You must register but it's free. [Report a dead link]
http://cafun.de/
[Screenshot]

Cellfighter

* Allows to create two rival colonies of artificial life and to place various auxiliary objects (sources of life, stones, food and poison) into the game environment.
* Allows a player to add cells in real time (without stopping birth-and-death process), but this player possibility can be limited by restrictions of input.
* Gives power to change rules of birth and death that is greater than in other implementations of Conway's Life.
* Automatically ceases the birth-and-death process if an autostop condition defined by user is satisfied.
* Keeps detailed statistics and uses it to calculate a score according to adjustable score rules. [Report a dead link]
http://www.terminalstudio.com/alife_features.htm

Civ Evolution
Game like Civilization with more strategic depth. WIP but nearly done. No sound fx yet. here. [Report a dead link]
http://c-evo.org/
[Screenshot]

Colonization
Yes, the classic from Sid Meier where you colonize the new world. . [Report a dead link]
http://www.worldoffreegames.com/factsheet.php?id=245
[Screenshot]

Deranged Raid
Freeware flight-sim and RTS. You have to get credits to buy components for your base. You must destroy the other team's base while defending yours. [Report a dead link]
http://www.playspoon.com/awf/index.php?id=33

Far Colony (WIP) , 36,000kb
Game of exploration and colonization. [Report a dead link]
http://farcolony.sourceforge.net/index_en.html

Simutrans
Transportation and economic simulation, like Simcity. [Report a dead link]
http://www.simutrans.de/english/simu/download.html
[Screenshot]

Virtual U , 17,308kb
Manage a university. High-quality graphics, like Simcity. [Report a dead link]
http://www.virtual-u.org/screens.html