A unique game starring Tux, the Linux penguin.

Tux Racer lets you take on the role of Tux the Linux penguin as he races down
steep, snow-covered mountains. Enter cups and compete to win the title! Tux
Racer includes a variety of options for gameplay, including the ability to
race courses in fog, at night, and under high winds.

You can also make your own courses with a graphics program such as The GIMP.

Tux Racer