I purchased the game on steam during the chrismas sale. However, I have a serious issue where the game constantly "flickers", like a strobe light. It's painful to look at, and can be seen in both the main menu (where you choose the profile), the introduction (company logo etc) and in the game itself. Turning on V-sync does nothing, nor does turning on or off fullscreen mode. (v-sync does reduce the problem, but only slightly. Might be observer bias).
The game is currently unplayable, as it literally induces headaches.
I have an NVIDIA Geforce GTS 250, I have a 1920x1080 resolution monitor. Running windows XP.
If I can't get this fixed I'll have to ask steam for a refund, because the lack of an options menu and the lack of changable settings in the ini menu are quite frankly appalling.
edit: updating the drivers fixed it. Still, the options menu is appalling.