Vega Strike is a free and open-source 3D action space-simulator game that lets you trade, fight, encounter new species and explore the vast universe in your spacecraft. Vega Strike has some inspiration from the Wing Commander game series and Star Trek with plenty of shoot em up action. The game is primarily single player but offers a multiplayer deathmatch mode online.
Mac OS X 10.5 or newer
Intel powered Mac
OpenGL compliant graphics card
Free download at vegastrike.sourceforge.net