Maybe you have played an online game called Desktop tower defense? It’s a game where you have to protect your desktop from loads of “creeps” that try to get over your table. If you have then you might also like MapsTD, a game where you have to protect a place on a map from being attacked by creeps. You can choose the map area yourself, and then you have the choice of the ordinary Google Maps, Google Satellite or watercolour background map. It’s a simple but good timekiller.