Don Jones, from Sapien, has written a neat bit of game code, which he calls PowerQuest. PowerQuest is a game snap-in for Windows PowerShell. PowerQuest is loosely inspired by the classic "Colossal Caves" text-based adventure game. PowerShell also provided a look at how to build PowerShell cmdlets using various programming styles. Don's also written a graphical map editor for the game.
You can get PowerQuest from CodePlex at http://www.codeplex.com/powerquest.