As promised, CellFactor: Revolution FPS - designed to showcase Ageia's physics-acceleration hardware - has been released for free to PC owners. It should work fine even if you don't have a PhysX card - the idea being to show you how important proper in-game physics can be and hopefully convince you to part with some cash for the added hardware. Propel yourself like an apple falling from a tree towards www.cellfactorrevolution.com for download links.
You can flick through yesterday's first-impressions piece for more details on the game's history and goals, but, to sum up, it was originally put together by Immersion Games and Artificial Studios as a tech demo to showcase Ageia's PhysX card and has since been built into a game of its own: a physics-heavy deathmatch-based first-person shooter with five maps, one of which has been specifically designed to bring machines devoid of PhysX cards completely to their knees.
There's a single-player mode that has you fighting against bots, various psi powers for manipulating objects (a big part of the physics demonstration, obviously), a range of vehicles and three character classes to master. Potentially getting in the way of success is the lack of an online mode (those physics calcs are too vast and chunky to work in real-time over anything less than a home network, it seems), but with the game now available that's the sort of observation you're in a position to put to the test. Give it a go, and let us know what you think.