If you’re looking for a little variety to your daily shootouts, then it’s definitely worth taking a look at what kind of games the Open Source space has to offer us these days. And we’re doing just that. From Monday through Sunday this week, we’re bringing you this series of what we think are seven great first-person shooters - all open source, all 100% free to download and play. Seven days, seven games. Today is day #3 and the game is:

#3: Alien Arena

Say hello to my little space gun..

Alien Arena is a MP sci-fi FPS with some robotic and funky Mars Attacks-type alien characters to choose from. Besides having some solid tried and tested FPS gameplay, it comes with your standard set of game modes, but also has a few surprises up its green alien sleeves.

Game modes include: Deathmatch (Free for all), Team Deathmatch, Capture the Flag, Deathball, Team Core Assault, All out Assault and Cattle Prod. As you can see, a few of the game modes don’t sound like your typical run-of-the-mill stuff. Let’s leave the fun of discovering what each mode is all about to you, but know that there are alien cows(!) involved.

The weapons in the game are also a bit different that what you see in most shooters, ranging from a very slow moving blaster to a disruptor (a quick firing rail gun). Every weapon has an alternate mode as well, from scopes on the disruptor to slow-moving homing rockets launched from the rocket launcher.

The current version of the game is 6.10, commonly known as Alien Arena 2007, with both Windows and Linux versions available. And Alien Arena 2008 is actually due out some time later this week, bringing along both visual and performance upgrades across the board.

Grab our RSS feed or be sure to check back tomorrow for game #4.

This series is a joint effort between That VideoGame Blog and a gamer who has played Open Source games to an extent where he even set up a bi-weekly online show about them over at SauceTheGame.com