Goat Attack!
In the time it took me to post about XNA Game Studio 3.0, I was able to download and install it, and create this amazing smash-hit title: Goat Attack.
Yes, it really is that easy to make games from the 1980s in about an hour. This one has a scrolling tiled backdrop, and SpriteBatch objects for the car, evil goats and various weapons. You drive around the deserted Greek Island taking out the goats, and well, that's about it. Classic stuff.
