I don't know if it's been mentioned before, but the fixed 60 FPS and 30 FPS options seem to cause the game to change it's internal rendering (meaning internal game speed) rate to those FPS respectively.
If you're running this game on a POS ancient laptop like I am (Core 2 Duo 2.8 GHz, ATI Mobility Radeon 4670 1GB), and your system can't output 60 FPS consistently when you've chosen "Fixed 60 FPS" in the Video Options, the game itself will seem to go into "slow motion". So if your system drops to 30 FPS, the game's effective speed will be halved.
The "solution" so to speak is to change it to "Fixed 30 FPS" (yeah, yeah I know..), and then the game will be at the correct speed even when your system is pushing only 30 FPS.
Just thought I'd throw it out there for those with crappy rigs like mine.
Otherwise, I'm having a blast of a time, I can set it to 1080p, 0x AA, HD textures, High Shadows and Motion Blur OFF (Seriously having it ON makes the game look terrible.) and maintain 30 FPS all the time. Using a 360 wired pad, which is good enough for this game.