Free Allegiance 

Allegiance is a free online multiplayer space game set in the year 2150, shortly after the Earth is destroyed by an asteroid. In this simulation game, the players are the pilots of spacecrafts varying from small vessels to large ships, all flying with other team members, whose main goal is to gain victory through various means including killing enemies and capturing or destroying enemies' bases. The game is not so easy to learn and play. It has complex controls, and it is based mainly on teamwork, coordination and tactics. But the Allegiance Academy will teach you the basics of the game online. The graphics and effects of the game which are accompanied by an enthusiastic and motivating music are wonderful. Flights and combats are made in a first person view in a 3D environment, with a top-down view of your immediate surroundings that help you to navigate and make quick tactical decisions of the moment. In order to play you will have to create a gameplay account and install Microsoft's .NET framework.