Starships Unlimited
Starting with one starship, explore the galaxy, uncover ancient alien artifacts and fight pirates as you expand your empire. In this game, starships are the heroes! Watch detailed space combat take place before your eyes. Research over 200 technologies from 4 ages. ... Use it to keep track of others or to steal some of their technology. ... Only one civilization can rule the galaxy. ... Will it be yours? ... Build up a spy network. ... Keep your worlds and starships up-to-date with your latest technologies.
http://www.apezone.com/install/stundemo.exe - 3Mb - Download - Screenshot

Starship Ranger
Your Matherplanet is suffered from invaders - extraterrestrials. Enemy aircrafts bomb the Earth. You are the last hope of the terrestrials. The best starship is prepared and well equipped. Don't lose the time, good luck! Your mission is rather complex. ... To rule your starship you can use a keyboard as well as a mouse as well as a joystick (great experience! ... All your skill and deftness are necessary for you in this intergalactic war. ... The advantages of the registered version: " 0ne hundred levels (100) instead of 20 in the unregistered version for never-ending game; " Three skill...
http://www.arcadestudio.com/downloads/starshipsetup.exe - 4Mb - Download - Screenshot

Planetary Defense
Planetary Defense is a space strategy game where you take charge of a planets defenses against waves of attacking aliens. Defend against missiles, multiple warhead rockets, cloaked starships, meteors, homing missiles and laser-armed satellites. Some of the 21 missions include orbiting moons... High score table, 3 Difficulty levels and a variable game speed for hours and hours of space-blasting fun! ... Superb graphics and low system requirements, only a 3MB download.
http://www.positech.eclipse.co.uk/planetarydefense_demo.exe - 3Mb - Download - Screenshot

Galactic Civilizations II: Dread Lords
Galactic Civilizations II: Dread Lords is the sequel to the award winning PC strategy game, Galactic Civilizations. Galactic Civilizations is a space-based strategy game set in the 23rd century in which players take on the role of leader of a space-faring civilization. ... A bonus pack has been released which added several new custom maps, scenarios, starship components, full-screen video tutorial support, AI tweaks, and much more. ... Galactic Civilizations II: Dread Lords will run on Windows 98, ME, 2000, XP, and Windows Vista.
http://stardock.cachefly.net/GalacticCivilizationsII_Demo.exe - 16Mb - Download - Screenshot

Netrek
Netrek is a free multiplayer online space battle game. Team up to battle with and against people around the world. As a player, you captain different starships to bomb armies, engage enemy ships and invade planets in order to expand your team's space empire and conquer the universe. ... Think that sounds easy? ... Think again, since you are always teaming up with different people as well as playing against different people, there is always a challenge. ... The ultimate goal being to wipeout the enemy race by battling your enemy with the spacecraft of you choice.
http://www.playnetrek.org/netrek/netrekinstall.exe - 2Mb - Download - Screenshot

Nether Star
The black depths of space has many mysterious secrets. People always looked on the night sky with hope and admiration. But not when enemies came at us from the stars. The enormous army of dark legions, destroying planets, came directly to the Earth. The governments of the Earth decided to use... You are sent to destroy alien aggressors and to save the Earth from enslavement. ... Your mission is to fly through hordes of enemy starships and to kill the head of the alien fleet - Commander Lord-Marshall.
http://www.ksysoft.com/nether/netherstar.exe - 8Mb - Download - Screenshot

Star Invader for Palm
Thank you for using Star Invader for the Palm, an improved clone of one of the classic games of the 80's. We hope you will enjoy playing this game so much as we did creating it! The goal is simple: Operate your starships to destroy to all enemies, defend the Earth by shooting the invading aliens... Start Level Select: You can play any level of the game. ... Top 10 Scores Kept: You can be on the Top 10 list if your score is high enough. ... Pause/Restart Game: You can pause the game at any time and resume later.
http://www.ibegroup.com/download/Invader_Palm.exe - 737Kb - Download - Screenshot

Star Invader for Pocket PC
Thank you for using Star Invader for Pocket PC, an improved clone of one of the classic games of the 80's. We hope you will enjoy playing this game so much as we did creating it! The goal is simple: Operate your starships to destroy to all enemies, defend the Earth by shooting the invading... Start Level Select: You can play any level of the game. ... Top 10 Scores Kept: You can be on the Top 10 list if your score is high enough. ... Pause/Restart Game: You can pause the game at any time and resume later.
http://www.ibegroup.com/download/Invader_PPC.exe - 9Mb - Download - Screenshot