Unles: Lunar Expedition Simulator

The Unmanned Lunar Expedition Simulator is a small 3D (OpenGL) game in which you control an unmanned moon vehicle. It is a two-player game that may be played either against the computer or against another player on the internet. There are two game modes: a racing game and a death-match game.
Technical stuff: The game uses rigid-body-dynamics for control of vehicle movement. It has a particle system based gun, 3D audio, and an online high-score list.

download here:   http://unles.sourceforge.net/download.html