mappy is a mouse detective. you move left and right in the [house] picking up items that the cats have stolen.
you can only move left or right, but you have to avoid the cats (you have a few items at your disposal including doors which can be opened or closed to keep the cats at bay) and microwave doors which emmit a pulse of energy that sweeps the cats away for a short period of time.
you navigate to the different sections and levels using the trampolines located at the bottom of the house, however bouncing on a trampoline 3 times in rapid succession will cause it to break. if you break through a trampoline located at the bottom of the screen, you will lose a life.
the object of each level is to recover the 10 items and avoid the cats. certain items act as a bonus multiplier increasing your point total.
bonus levels appears every 3 levels (?), where you have to capture 10 balloons.