If you pre-order Prototype 2 from GameStop, you'll get a modified version of the game's Bio-Bomb ability. As opposed to tossing infected enemies and watching them explode, the "Butt Kicker" ability allows you to kick them. In the butt. Really hard.

It's perhaps a strange motivation for pre-orders, but, as the video above makes clear, it's hard to deny the maneuver's effectiveness.