Mappy is a platform game for the Nintendo Wii where players control Mappy, a police mouse tasked with retrieving stolen items from the Mewkies, a group of mischievous cats. Players navigate a six-story mansion filled with hallways, using the Wii remote to move and interact with doors. The objective is to collect goods while avoiding the Mewkies that seek to thwart Mappy's efforts.
The player guides Mappy the police mouse through the mansion of the cats called Mewkies (Meowky in the U.S. version) to retrieve stolen goods. The player uses a left-right joystick to move Mappy and a single button to operate doors. The mansion has six floors of hallways in which the stolen items are stashed.