I just finished my first little game with this thing...
In this game you are a ship protecting a planet from incoming asteroids.
Controls:
360 controller:
Left Joystick -- Move ship left and right.
A -- Shoot
Right or Left Trigger -- Change Weapon.
Keyboard:
Left and Right Arrow Keys -- Move ship left and right.
Up and Down Arrow Keys -- Change Weapon
Space -- Shoot
The weapon you are using is shown in the top left corner. The stronger the weapon you use, the less points you get for destroying an asteroid. Levels progress at timed intervals and more and more asteroids come down. You lose when one of them reaches the planet.
Screenshot:
http://www.rocketsoft.gm-school.uni.cc/uploads/ADScreen.JPG
Game File:
http://www.rocketsoft.gm-school.uni.cc/uploads/AsteroidDefense.rar
All in all this game took around 24 hours to complete, and comes in at 601 lines of code(including comments.) Awesome job Microsoft, I can't imagine making a game like this using purely DirectX in that amount of time and with so few lines of code(I'm sure I could've gotten it lower if I knew the language better.)