Civilization: Call to Power is a turn-based strategy game developed by Activision for Microsoft Windows as an attempt to capitalize on the success of the Civilization computer games by Sid Meier. It was ported to Linux by Loki Software, as well as BeOS, becoming one of the very few commercial games for that operating system. A sequel, Call to Power II, was released 18 months after the original. The sequel could not have "Civilization" in its title because Activision did not have a license for the "Civilization" name for a second game. Gameplay Timeline and epochs One of the most noticeable differences from the previous Civilization games is that the timeline of the game does not end in the 21st century, but rather goes to the year 3000. There are five epochs in this game: Ancient Age, Renaissance, Modern Age, Genetic Age, and Diamond Age. Call to Power adds a more thorough space colonization as well as sea colonization, with the appropriate technological advances (available in the Genetic Age). Terrain features Similar to Civilization II, the game uses an isometric view, although each tile is actually two separate tiles: the space level on top of a "terrestrial" level (thus, this game has a z-coordinate to represent position). Players can toggle between "Earth view" and "space view". All land and naval units are exclusively terrestrial, although most land units can be launched into space inside a cargo pod by a rail launcher in cities or via a space plane. Space fighters and space planes can freely travel in space and in the atmosphere. While the SWARM warrior can survive in space as well as the earth, it cannot launch itself into space. There are also some units that exist in space exclusively (i.e. cannot make a re-entry into the atmosphere) such as the Star Cruiser, the Phantom and the Space Bomber. Space produces no resources, as it is a vast void. However, once a space colony is built, players can build food pods and assembly bays to produce resources for the colony. "Water tiles" are also divided into several types. After submarines are available, the type of tile in oceans can be seen (e.g. continental shelf, deep sea trench, rift, etc.). Once the technology for sea colonies is discovered, undersea tunnels can be built to link to other sea colonies and dry land. Fisheries and undersea mines can also be built