Quickshot Trackball
The
Quickshot Trackball was an
NES controller with two buttons, a limited-movement
trackball, and a switch to set it for either a right-handed or left-handed player. Like most non-standard NES controllers of the time, it was difficult to work properly, as games usually were not designed with it in mind. An exception is
Marble Madness, which turned out to be a natural match for the controller.