The player controls an anti-aircraft cannon, located at his or her point-of-view, with a crosshair on the screen.
Players move a crosshair around the screen to aim and shoot at mobsters one at a time.
The simple gameplay involves the player controlling a fixed turret on a tank shooting oncoming alien enemies through a cross-hair target.
A monocular w/reticle is a telescope with a built in scale that can be used to accurately measure the width of objects such as the diameters of trees from a distance.
The player turns a control knob to position the CRT beam on the screen; to the player, the beam appears as a dot, which represents a reticle or scope.
The reticle is illuminated by an electronic light source (an incandescent light bulb or, more recently, a light-emitting diode) or by ambient light gathered behind the reticle via an opalescent window or fiber optic light pipe.