Bulletstorm is a game about killing people in ridiculous ways for points. The tools and abilites Epic have shown so far have included a glowing leash with which to throw enemies around, and the ability to kick leashed enemies in the head as they sail through the air in slow motion. There aren't many developers who would look at early demo and say "there's not enough cannonballs. What this game really needs is a gun that fires cannonballs," but that's exactly what Epic have done. Read on for more information, and footage of a gun that fires cannonballs.
The new weapon is actually called 'The Bouncer', that's because if you charge up the shot the cannonballs it fires will stick around, bouncing up and down, causing carnage in the surrounding area. The cannonball can then be leashed or kicked into groups of enemies for massive combo bonuses including 'Direct hit!' (+25 points), 'On the ball!' (+50 points) and, er, 'Facial' (+50 points).