Everything was going great in the first hour and a half into the game until I got to a part in the game where the facility collapses and you are submerged underwater. After that I got a lot of graphical glitches, weird textures popping in and out, and it was basically unplayable. The game did not crash but I had to quit since it was basically impossible to move, the game would freeze intermittently. Immediately after quitting the game my system locked up (spinning beachball) and I was forced to hard reboot.
PS I tried to attach the log file directly to this post but it told me the file was too large, so here is a direct link:
https://dl.dropboxusercontent.com/u/60341/hpl.log
Here are a few screenshots: