This project lets you send a stream of particles into a system of planets - just for fun. Mouse down to set the starting point, the mouse down again to start launching. Velocity is proportional to the distance to the mouse pointer and particles launch toward the pointer.
A remix of SystemDefense. Maybe this could become a game of some kind - based on how long your particles orbit before getting absorbed or flung out of the system? Or perhaps there's a target planet you try to hit?