When I move the mouse fast, the aim slows down. When I move the mouse slow, the aim speeds up. This is possibly due to the fact that mouse acceleration toggle doesn't work. I'm not sure. If you ask me it should be 1:1 anyways. It is very annoying to play like this. I do have an Xbox 360 controller plugged into the computer, but just tried to unplug it to see if it had any effect. I feel like there may have been a slight change but it could just be placebo.