Rocketblitz is another awesome shooter game based in a 2d space environment. You control a spaceship as part of 1 of 2 teams and battle against each other in a 'capture the planet' style game mode.
When playing as a guest you will only have one type of spaceship available which comes with a default rocket launcher weapon, however if you choose to sign up to their site you'll have access to several other ships including one with a mini-gun as featured in there how to play video. As this game has 2 primary objectives your job is to take control of the territory in the form of planets scattered around the map whilst blowing up enemy ships. To take the lead you're going to need some excellent teamwork so make sure to use the in game chat to its fullest and take command of your very own fleet!
Use WASD to control your ships movement and use the space bar to shoot your weapon.