Asteroid Wars
Asteroid Wars is a remake of the classic space shooter game "asteroids", that originally came out in the arcades in 1979.

The objective of Asteroid Wars is to destroy asteroids and saucers. The player controls a triangular ship that can rotate left and right, fire shots straight forward, and thrust forward. Once the ship begins moving in a direction, it will continue in that direction without player intervention unless the player applies thrust in a different direction.

There is more information on its home page.

You can download the source from github.