Here's another I've just recently found: Foldit. It's been around for a while. Basically, it's a puzzle game in which players tackle actual real life scientific problems. Just three years ago Foldit players solved in 10 days a problem that baffled experts for 15 years. You don't have to have a scientific education or background to play it.

Here's what Wikipedia has to say about it:
"Foldit is an online puzzle video game about protein folding. The game is part of an experimental research project, and is developed by the University of Washington's Center for Game Science in collaboration with the UW Department of Biochemistry. The objective of the game is to fold the structure of selected proteins as well as possible, using various tools provided within the game. The highest scoring solutions are analysed by researchers, who determine whether or not there is a native structural configuration (or native state) that can be applied to the relevant proteins, in the "real world". Scientists can then use such solutions to solve "real-world" problems, by targeting and eradicating diseases, and creating biological innovations."

Desura Freedom Friday - Oct 17

It's not announced yet, but these seem to be the likely releases it will include:


Annex: Conquer The World

Annex: Conquer the World is an anime themed real time strategy game that brings fast paced combat with a diverse arsenal. Play as one of four factions: The East Ocean Alliance, the NEO Republic, the Shadow Organization, or the Renegades as they struggle for dominance all over the world, competing for a priceless red mineral. The game now contains 4 factions, over 30 tech trees, original maps, and tileset. Built using open source RTS MegaGlest, the focus of the game is multi-player and single-player skirmishes. However there are also scripted scenarios/missions!


UnReal World

UnReal World is a combination of roleplaying game and a survival simulation. In a world inspired by iron-age Finland you can track animals, set traps, hunt with bows and spears, tan hides, go fishing, pick berries, cook food, sleep in a temporary shelter or build a log cottage, trade with the villagers, craft items, etc. It has a randomly generated map, skill development and a detailed wounds and combat system. The item crafting is moddable.


Delta Loop

Take control of the most advanced combat spaceship, in a desperate last stand in outer space. Your mission is a simple but tough one: decimate all the enemies before they decimate you. Get ready to fight endless waves of increasingly challenging hostile ships, equip powerful weapons and enhancements, and put your skills on the line. Will you be able to earn a place for yourself in the elite pilot ranks?". Delta Loop is a fast-paced space arcade shooter with a big focus on gameplay. Anyone -from people not used to action games to seasoned arcade experts- can have a fun and skill-rewarding experience.


Cubified

Cubified is an action-platformer in which you control Cuby, a gray blob-like creature able to transform into a cube at the press of the spacebar.

They are all new to Desura. Aren't Freedom Friday games usually games already on catalogue that become free?

No, often they are released on Freedom Friday. It's a good promotional event for the games as well as for Desura. Sometimes older titles make it in there, but new stuff is typically the case.

Gray Blob-Like Creature, or: How I Learned to Stop Worrying About Graphics and Make an Indie Platformer :P

Heh! Most of you here are probably too young to remember these things, but it reminds me of those "type-in games" you'd get in early computer magazines. :)

Ha! Wow, I vaguely remember those, though never played one.

Got it right. :-)

Cool, thanks! :)

Thank you both for this info. UnReal looks particularly interesting, and the music for the trailer is soothing, primal, I dig it very much.

That's the one I grabbed myself from this offering. It looks refreshingly different, and I like the premise.

Thanks for the headsup for Unreal World, been looking at it for a while and at this price its rude not to download it !

As SCPM posted, there are free old Apogee games (DRM-Free) signing up at 3D realms site:

Alien Carnage
Arctic Adventure
Bio Menace
Major Stryker
Monuments of Mars
Pharaoh's Tomb
Stargunner

OMG! They have "Death Rally"!! "Death Rally" is back!!!
** does celebration dance**