This is a port of an MS sample available at the XNA website
OK first off i did not create this I simply ported it from windows to the zune and changed the graphics a little bit, i take no credit for the actual engines.
So fuzzy logic is an engine, it has 3 AI features, a tank follows mice (yes yes computer mice) according to 3 different AI patterns up and down allow you to change those, and left to right allows you to modify the parameters of those.
Fuzzy Logic.rar
so have fun, according to the Microsoft license you can use this in your games.