X-COM: Terror from the Deep

X-COM: Terror from the Deep is a science-fiction strategy game developed and published by MicroProse for MS-DOS in 1995. It is the sequel to UFO: Enemy Unknown, known as X-COM: UFO Defense in North America, and transfers the struggle against an alien invasion from the surface of Earth to its oceans. A PlayStation conversion followed in 1996, while a Windows version appeared in the 1998 X-COM Collector’s Edition.

The story takes place in 2040, four decades after the destruction of the alien base on Mars. A surviving transmitter on Cydonia has awakened an ancient extraterrestrial force that has remained dormant beneath Earth’s seas for millions of years. As attacks on ships and coastal cities increase, the governments of the world reactivate X-COM and place the player in command of the organization. The ultimate objective is to locate and destroy T’Leth, the enormous alien vessel concealed beneath the Gulf of Mexico.

Gameplay retains the two-part structure of its predecessor. On the real-time GeoScape, the player builds underwater bases, monitors alien submarine activity, manages finances, recruits aquanauts and assigns scientists and engineers to research and production. Detected alien vessels can be intercepted by X-COM submarines, while recovered technology gradually provides access to improved weapons, armour and craft. Funding depends on the confidence of participating nations, making successful interceptions and responses to terror attacks essential to the organization’s survival.

Combat takes place in the turn-based BattleScape, where squads explore isometric underwater environments, sunken alien vessels, ocean-floor installations, ports and civilian ships. Every soldier has a limited supply of time units for movement, firing and other actions, while morale, reaction fire, destructible scenery and hidden enemies create considerable tactical uncertainty. New additions include close-combat weapons and lengthy missions divided into multiple stages. Some equipment functions only underwater, requiring the player to adjust the squad’s armament before surface operations.

Terror from the Deep closely follows the structure and engine of UFO: Enemy Unknown, but introduces new graphics, creatures, technology and mission types together with a substantially higher level of difficulty. Large maps, heavily protected enemies and multi-stage terror missions can make battles slow and exhausting. Early releases also contained errors in the complicated research tree that could prevent essential discoveries if certain subjects were examined in the wrong order, although patches and modern source ports address several of these problems. Despite its limited mechanical innovation and occasionally excessive difficulty, the oppressive aquatic atmosphere and proven combination of global management, technological development and tactical combat make it a substantial and memorable sequel.