Simutrans is a transport and economic simulation game. Simutrans has not yet reached production state, but it is quite possible to build big transport networks between the industries and cities.
The player can create bus and rail connections and transport passengers, mail and goods in and between cities and industries. Even passenger ferries and oil tankers are included in the game. Goods are produced by industries from raw materials, sometimes over many steps of intermediate products. i.e. coal and iron ore are needed to produce steel in a steel mill. Oil may be transformed to plastics in a refinery. Plastics and steel are used to build cars by the car industry. Finally the cars are sold in the cities which need gas to run, which will also be produced at the refinery.
All goods need to be transported which is the ultimate aim. Transport the goods and allow industry to thrive but be careful not to destroy the environment!
