Team up with the Aliens or the Humans and then show the other side who owns the galaxy. Kill enemies or mine from asteroids to make money. Spend that money upgrade your ship and weapons, and then destroy enemies or their bases.
Use WASD to fly around the map (which is divided into sectors). Shoot with the left mouse button, and change weapons by scrolling. Visit friendly space stations and dock with them to upgrade your ship or buy weapons.
There are a lot of places you can visit on the map, and your HUD points you in the direction of important spots, from asteroids to space stations.