Spore Galactic Adventures - Will Wright's 2008 alien evolution game gets a proper expansion pack this week as gamers will be able to explore planets with missions supplied by the game's development team. You can create your own Space Captain to explore strange new worlds. Publisher Electronic Arts has also put in a mission editor for the expansion and even the Robot Chicken TV show's writing team is using it to make their own weird stories that you can download for free.

Dawn of Discovery - This historical trading-strategy game from publisher Ubisoft is actually the latest game in the Anno series of titles that are big hits in Europe but so far have not been as successful sales wise in the US (hence the title for the US version; it will be titled Anno 1404 everywhere else). You can download a playable demo of the game right here at Big Download.

ArmA II: The sequel to the military shooter-sim from developer Bohemia Interactive has already been released in Germany and will be available via Steam download on Friday (It's due in retail stores next week). Players will fight on foot, in vehicles and in the air on a massive open world island.

Transformers: Revenge of the Fallen: Activision released this latest movie-to-game adaptation as the robots in disguse do what they do best; transform and blow a lot of stuff up. The big improvement over the last Activision Transformers movie game is the addition of multiplayer modes into the mix.

Fallout 3: Point Lookout: Bethesda Softworks whips out their fourth downloadable mini-expansion for their hit RPG game with this one located on the marshlands of Point Lookout, Maryland. It will be released via Games For Windows Live for 800 Microsoft points on Tuesday.