At the last conference I have attended there was a presentation of a funny programming game. Its easy to understand, easy to learn and exciting to get a higher score.
What is to do? Just program the behavior of ants to let them collect as much as possible food. For that task there is a simple API with only a few easy to understand commands. Basicly you only have to derive from a given BaseAnt class and overwrite the existing functions. Whatever you program here the ants will do it!
How does it work? You implement the behavior of your ants and start the game. A game controller calls the methods of your ants everytime an interesting event occurs e.g. your ant is near a food resource or the ant becomes tired. After the game is started you can do nothing more than watching the small black worker running in a virtual world. For people with a 3D accelerator card even in 3d and not flat.
You can either use C# or Visual Basic for developing your own ant peoples. All you need to start you can find on the coding4fun website from Microsoft.