CityRunner is a futuristic search-and-rescue driving game featuring a 3D voxel-based environment, all in 4KB (!) of executable size. The player sits behind the wheel of a polygonal police car (shuttle? hovercraft?) and gets to zoom along the city streets in search of trouble hotspots, indicated by flashing buildings, which must be located and bumped against to rescue the distressed citizens therein. The objective is to save as many targets as quickly as possible, without running out of time or crashing the vehicle in the process. Each assignment starts at the station, with a time limit, a set number of targets, and full shields to protect the car against impact. The cutting-edge vehicle can drive forwards and backwards with equal ease, and is equipped with a speed-boost pedal for those long straight streets. Points are awarded for saving buildings and completing missions - swift action is rewarded with higher scores. Once all buildings have been saved, it's back to the police station to recharge the shields and get a new assignment (with more targets). Unsafe driving may result in nasty collisions with buildings, which take a toll on the shields; wreck the car completely (or run out of time) and it's game over. For navigational aid, an interactive map screen can be called up at any time and scrolled / zoomed / rotated at will.