Bad luck there, mate...
I never really trust system requirements...they will only assure you that you can play the game like a slideshow...
Honestly I think there should be many more options, to customize the visual settings instead of High | Medium | Low...and the Brightness...(wth?)
I have a P4 @ 2.7 512 DDR and GeForce FX 5200...but I can only play the game in the lower quality settings...I don't get it, I've played games with much better visuals in higher resolutions. Maybe they should work on the engine..