1)   Titan Attacks 1.1
Save the Earth from evil alien invaders from Titan! Fight your way across the solar system to defeat the aliens on their homeworld. Upgrade your ship with bigger guns from bounty money. Defeat the alien mothership!

 2)   Scott's Space Invaders 1.6
Scott's Space Invaders is like the good ol' space invaders that you remember, but with a few additional perks and powerups, some new tricks, and designed to operate on modern PC hardware. It requires windows XP and DirectX 9.0 or higher.

 3)   Political Invaders 1.4
Throw pies at the Politicians and their henchmen. The game plays similarly to the popular Space Invaders arcade game. Features 3D rendered graphics, and requires DirectX 9.0 or greater. Fun, exciting, and free!