The guns in “District 9″ were, well, “off the chain”. They looked cool, sounded cool and demolished objects. While Nerf’s Swarmfire probably won’t achieve the latter two of those things, it most certainly bares a resemblance to the movie’s weaponry.
The Swarmfire takes 6 C batteries, enabling the gun to fire 20 darts in rapid succession. There is a video below from Urbantaggers and it looks like it can shoot 2 darts per second.