Source: Wikipedia, Imperialism (video game) , available under the CC-BY-SA License. Imperialism is a turn-based strategy game for Microsoft Windows and Apple Macintosh computers, developed by Frog City Software and published by Strategic Simulations, Inc. (SSI) in 1997. In Imperialism, the player is the ruler of a 19th century country, and must build an empire. Imperialism was followed by Imperialism II: Age of Exploration.