Darwinia is a game created by Introversion software for Windows and Linux and ported to Mac OS X by Ambrosia Software. The game takes place in a simulated theme-park, in which live advanced AI sprites named Darwinians. The sprites look like little green 2-D stick figures. The Darwinians were created by a computer scientist named Dr Sepulveda, who you meet upon entering the virtual world.
Immediately upon entering the first area you see, "The Garden," you are accosted by Sepulveda, asking you who you are and how you got in after he thought he'd shut down all outside connections. He tells you to make yourself useful by helping him save the Darwinians from a vicious virus that has all but completely taken over his computer systems.
You are greeted then with the control system for the game. On pressing ALT you are given a task manager, into which you can draw gestures that allow you to pick and run a program on the computer. You can run two programs to start out with: the Squad and the Engineer(a very direct reference to the Recognizer in Tron). With the squad you begin the process of destroying the infection with their laser weapons at your control. Once you've destroyed the infection in The Garden, you must strike out into the rest of the Darwinian's virtual world, ridding them of their attackers.
The game is a real time strategy(or perhaps runtime strategy) that takes place inside a game. You have to master a strategy based in large part on the AI of the Darwinians who you have NO control over whatsoever. In the combination of arming your own low-AI squads and the high-AI Darwinians you must lead them to take back their home from the virus infecting it. It works surprisingly well, for something that seems like Lemmings the RTS.
Another winning game from Introversion. The graphics are in their style, basic and flat while at the same time pretty. They used their premise as an excuse to make the 3-D sprites extemely pixilated and simple and the graphics very basic. The land is all in large polygons and not highly developed, it just juts out of the water and is bright. This style could not be better implemented, because it allows a large number of sprites to be active on a screen without the need for high processor power. While simple they manage to make the graphics consistently pretty.
The game is made interesting by its simulation of its premise. If you were building a graphically oriented world to house an advanced AI program, then you would not require graphics cards a plenty on your mainframe, you would make the graphics simple. This simplicity allows them to explore the gameplay and allows us to suspend our disbelief enough to enjoy the game.