Mini Metro (2015)

Its spare diagram makes the passengers and connections the whole game. Station shapes stand in for destinations, so a useful interchange can solve a problem that another train on an overloaded line will not. New stations and limited weekly resources keep asking you to redraw the map. There are no detailed signals or timetables to learn, but the standard growing-city game eventually overwhelms the network. It is the compact choice for enjoying the logic of a service rather than its rolling stock.