I downloaded the Mafia 2 demo on Steam and tried it out. It was average, very much like GTA IV, but with less weapons it seemed. But my opinion about the game isn’t the point with this blog post. 
When I closed the game was my screen brightness very low and it was really dark. Reopening the game didn’t solve it, but opening another game in fullscreen did. I opened CS 1.6 and after that was my screen brightness back to normal.