Keep in mind that this is a demo and isn't completely optimized and you may want to check around and see what everyone else is using and how they're framerates are with their setup and hardware. I had no problems installing the game, but I'm running on medium/low graphic settings at 800x600 32bit, FSAA2x, AF2x. It looks and runs alright until the hud gets cluttered with effects and then I get a little stutter. I'm very happy with the demo so far though, but I'm definitely upgrading for the final release. I can get the "gooey graphics" when I set it on "high", but it's unplayable at that frame rate, but nice for screenshots. :)
Athlon 1.2
256MB PC133
SB Live Value
G4 Ti4200 64MB
**Intel is dropping CPU Prices in the last part of October, so you may want to plan your upgrades around that time.