«

[The Coop]

None of the above actually.

The game normally requires the CD to be in when you play it. It checks for it when you try to start a game (new or continue). Whoever hacked the game either tinkered with the executable in other ways, or else they might have used the executable from the beta of PS that was released. Either way, it resulted in the sped up strafing, a missing mouse-look button, and the unadjustable mouse sensitivity.

It's the only cracked version of the game I've been able to find, and I haven't found anything about what exactly the game looks for when it checks for the CD (a file? a line of code on the disc?).