X-COM: Terror from the Deep

X-COM: Terror from the Deep is a strategy video game developed and published by MicroProse in 1995. It is the sequel to UFO: Enemy Unknown (X-COM: UFO Defense), and the second part of the X-COM series.

Story
Terror from the Deep is set in 2040, decades after the first Alien War was won, when a mysterious new alien menace begins to emerge from the Earth's own oceans.

Gameplay
Terror from the Deep plays out underwater, with base-building and combat all being submerged beneath the waves. The only time the game moves onto dry land is for terror site missions (when the aliens attack a port, ship, or island). However, the difficulty level has been substantially raised and there are a number of new features.

Terror consists of several parts. The first is the GeoScape, a global view of Earth. Here the player views alien and X-COM craft. The BattleScape is used for combat between squads of aliens and humans, and takes the form of a turn-based battle from an isometric view. Underwater battles use the same physics as the ground ones, even as many of the underwater weapons can be used on ground.

Resource management is also present, as the player must hire and dismiss staff, buy and sell vehicles, weaponry, ammunition and items, and build and expand bases.

Aliens
While the aliens and overall atmosphere of the original game was influenced by extraterrestrial life in popular culture, TFTD has a darker theme influenced by the works of H.P. Lovecraft, including the appearance of the Deep Ones (one of the alien races, the Tentaculats, is even described in-game as "not even the depths of a Lovecraftian nightmare could spawn such as this indescribable creature" ). The game has eleven fictional races of alien beings. Each race has various strengths and weaknesses, and some races are dependent on other races.

The aquatic aliens came to Earth on a large ship that crashed into the ocean 65 million years ago and supposedly caused the extinction of the dinosaurs. Many of the races from Enemy Unknown parallel these races, and some are supposed to have common ancestors. Several of the races have some source in Lovecraft's Cthulhu Mythos, and their main base (the mothership into the Sigsbee Deep) is named T'Leth, a reference to R'lyeh, a submerged alien city from Lovecraft's short story "The Call of Cthulhu" (Cthulhu itself is also referenced there in the form of the chief alien in The Tomb room which is the game's final objective).

Development
According to Mythos Games, developers of UFO: Enemy Unknown: "After completing UFO, MicroProse wanted to do a quick follow up within six months. We said that this was not feasible, and if it were possible it would be little more than the same game with different graphics. Instead we started work on X-COM: Apocalypse, which was much more ambitious. Once UFO/X-COM was clearly known to be a success, MicroProse suggested that we license the code for them to develop their own sequel. The rest is history."

Reception
Terror was received very well and the PC version holds an average rating of 86% according to Game Rankings. GameSpot summed Terror up with "Apart from new art and a handful of new combat options, this is exactly the same game as UFO Defense, only much more difficult." PC Gamer stated "Terror From The Deep is not only a great sequel to UFO but a superb game in its own right."

Re-releases
On May 4, 2007, X-COM: Terror from the Deep was released on the Steam platform by 2K Games, who has inherited the franchise.

The game has been also re-released as part of the compilations X-COM (Collector's Edition) by MicroProse in 1998, X-COM Collection by Hasbro Interactive in 1999, and X-COM: Complete Pack by 2K Games in 2008 and 2K Huge Games Pack in 2009.