No Gravity leads PSN update

Originally created as a PSP homebrew application in 2007, Anozor's No Gravity: The Plague of Mind ($9.99) is a 3D space shooter featuring customizable ships and 31 missions. The game lets players dogfight in first-person or third-person views, and features a variety of objectives from escort missions to Star Wars Death Star-trench-run-inspired assaults on massive space stations.

Although that's the only full game being added to the PlayStation Store this week, there are a variety of new demos that players can check out to preview upcoming games. First and foremost, Sony is releasing a free sampler for the much-anticipated first-person shooter Killzone 2. Beyond that, gamers can grab demos of Tom Clancy's HAWX and Major League Baseball 2K9.

The flood of downloadable content to the service is also continuing unabated. This week's notable arrivals include the Buzz Quiz of the Year 2008 pack ($5.99). The Buzz Quiz TV add-on tests players' global knowledge of the year that was, and can be played in any of the game's normal modes. As for PSP DLC, the NIS America action game Prinny: Can I Really Be the Hero gets another stage with Flonne's Castle ($3.99). As the name of the stage implies, Disgaea character Flonne serves as the level's boss.