Firstly, Mafia II PC (demo) doesn't show grass on the ground. Why?
This happens whether settings were low/high or activated/deactivated(like AA)
Secondly, it looks like graphics tries to draw something on the ground and in the whole space of Mafia II demo, this appears when big flowers are drawn on streets and on the ground. Also, I can see like blue/grey/brown lines upon the air, but usually those (spiking)lines are on the ground.
Lastly, all graphics aren't drawn, there's sometimes parts of street's drawn to one color, like brown.
Images:
1. No grass, giant flowers and lines on the street
2. No grass, spiking lines upon the air
And I repeat, this happens on all settings' types and it shouldn't to happen due PC hardware. And sorry my bad English.
My PC hardware:
Core 2 Duo @ 3.0Ghz E8400
ATI Radeon HD 4870
Windows Vista 64 Ultimate