Playing Fly Swatter is pretty simple. Select New Game from the File menu, and a fly appears on your screen. Your job is to use the mouse cursor to swat it. Just move the cursor over the fly and press the mouse button to swat the fly, and a new fly will appear. If you don't swat the fly after one second has passed, the fly leaves and another one appears. Your score is displayed in the lower-left hand corner of the window. If you hit the fly, you score a point.
If not then, no point! Hah easy! Everything can be customized from the time the fly stays till the scoring method.