Game freezes at loading screen

I try to boot the game; and it appears to freeze in the loading screen, seemingly to crash silently. There's *no* hint at what might be the problem, the game just freezes, and holds on the loading screen. I am completely unable to turn the game off, turning Steam off doesn't help. In a whole, it appears that the entire Windows UI breaks. 

Trying to reboot the computer locks the computer into a "restarting" screen limbo. I had to resort to doing a hard reboot (holding the power button) for the computer to start behaving again. I unfortunately can't add any images or anything else because I can't use the explorer, not even Task Manager behaves as it should.