Space Alien Invaders
Free arcade style space shooter game for the PC.
http://www.freewareshareware.net/download/sai.exe - 1Mb - Download - Screenshot

Typing Invaders - Free Typing Game
Typing Invaders is a REAL arcade game, in which you are escaping from invaders, shooting and trying to hit invaders. This is no fake - you are playing space invaders ! (You are not just typing characters). With this free typing game you WILL have fun, but don't worry, by playing Typing Invaders... Improve your typing skills with this free typing tutor - typing game !
http://www.giletech.net/Typing-Tutor/TInv_Setup.exe - 1Mb - Download - Screenshot

Spiders Invaders
Free Spiders Invaders Screen Saver created using Active Media Eclipse v. 4. Create your own Invaders Screen Saver..... easily and quickly ..... www. active-media-online.
ftp://ftp.active-media-online.com/Download/Spiders_Invaders.exe - 192Kb - Download - Screenshot

Cash Invaders
Cash Invaders is a space shooting game for MS-DOS. You shoot aliens to earn money, with that money you can buy power-ups. There are 100 levels plus 9 bonus levels. The game mixes elements from Space Invaders, Blood Money, SpaceBastards and some other games. ... All graphics are raytraced with 3D Studio Max.
http://members.home.nl/bas.de.reuver/cashinvaders/invader.zip - 416Kb - Download - Screenshot

Incoming
A real free must-have-game for the fans of classic arkanoid. Free to play. A great old arcade game with new features providing you with some hours of real pleasure. All you need is Flash 5 player to enjoy the game. There are brown invader planets moving at the top of the board that drop smaller... The goal of the game is not to let the invaders fall down onto the bottom of the board. ... An addicting game with simple rules. ... Develop your tactics and spend your time with use to your mind. ... Bright colors, real drive and pleasure.
http://gameyard.com/free-games/incoming_gy.exe - 411Kb - Download - Screenshot

Scott's Space Invaders
They arrived one day. They attacked the outpost. Funny little green guys shooting purple energy zigzags. All would have been lost were it not for the lone defender in his little ship. He fought them. Wave after wave. They only kept coming faster and faster. ... 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. ... Perhaps we'll never know... ... Did he ever defeat them all?
http://www.sb-software.com/spaceinvaders/sbvade16.exe - 3Mb - Download - Screenshot

Alien Invaders Attack!
Free arcade style space shooter game for the PC.
http://www.sci-fi-game.com/download/aia.exe - 4Mb - Download - Screenshot

Star Reaver
Star Reaver is a freeware arcade style space shooter game, available for free download. Defend your ship from dive bombing alien space invaders. Grab the power ups for powerful new multi-directional weapons that shred the marauding invaders. Free download available for PC and Mac.
http://www.freewareshareware.net/download/sr.exe - 2Mb - Download - Screenshot

Santa's Invaders Screen Saver
Free Santa Screen Saver Invaders game created with Active Media Eclipse v. 4 - download a Trial copy of the software that created this Screen Saver from www. active-media-online.
ftp://ftp.active-media-online.com/Download/Christmas_Screen_Saver.exe - 194Kb - Download - Screenshot

Jumpix
The XXII century. Our Earth is in danger. The invaders want to capture it and make their colony. For a long time the Earth was covered with a protective sphere. But the invaders have invented new weapons to destroy the protective sphere. The only chance to protect the Earth is to use a... You are given an opportunity to defeat of the invaders and get to the Space Intellect. ... By means of energy potential your spacefighter will get one of the highest levels. ... Remember! ... If you hit the mark you can use the energy of enemy warship.
http://www.gamexzone.com/files/jumpix.exe - 3Mb - Download - Screenshot