Solar Chiefs Online, The Planet Wars

Solar Chiefs is a multiplayer game. You fight as a Planet or Colony with many different weapons.

 The gameplay is easy. You have a short amount of time to aim your weapons and maybe also move your Colony. In the same time up to 3 human enemy's doing the same. Hit them with a Missile, a Laser or a Newton Gun (My favorite ;) and many other Weapons and try to kill them all!
The last Colony alive win and level up which will give you access to new weapons and systems

Give it a try: http://www.kongregate.com/games/Mygame/solar-chiefs
(Warning, Solar Chiefs can be addictive)