http://arstechnica.com/gaming/news/2011/02/bulletstorm-and-you-how-to-get-it-playing-nice-with-your-pc.arsQuote:
Turn this into a PC game
You'll want to undo the damage that consoles have done to this port. Go into the control options and turn off the aim assist. You have a mouse and keyboard, so you don't need it. There are multiple controls mapped to the same key, such as sprint and jump on the space bar, and the "R" button to use things and also to reload. If you'd like to split this items to different keys, you certainly can.
Also, if you notice your mouse controls feeling off, there's something you can do about that.
