In this video I altered the physics gravity, essentially making it so that although my feet are firmly planted on the floor, the props and etc. around the level would float toward a certain direction, essentially making a WALL their floor.
I play with this theory in one of the Nova Prospekt levels, the singleplayer equivalent of dm_lockdown in HL2DM.
The song/mix is the Neural Impulse She Special, remixed by myself. She's music can be found at www.myspace.com/sheofficial