InstantAction.com has just launched the open beta for their web-based first-person shooter Fallen Empire: Legions. Think of it as Tribes light, with two different classes, two different maps, and two different gameplay modes currently available for your quick and dirty gaming pleasure - capture the flag and deathmatch. All you really need to know is that it's a relatively simply yet generally satisfying FPS with jetpacks.
Playing requires you sign up for an account at InstantAction.com, GarageGames' web-based gaming portal, which is completely free of charge and gives you access to the rest of their game stable as well, including Marble Blast Online and Rokkitball. Hop on over and give it a try!