X-COM: UFO Defense is a strategy game designed by Julian and Nick Gollop of Mythos Games and published by MicroProse in 1994. Julian Gollop started the project as a sequel to Mythos Games' 1988 game Laser Squad, while MicroProse's Steve Hand designed the Geoscape interface and came up with the name X-COM. The PC version took 30 months to develop, cost about £115,000 and was nearly cancelled twice.
The game is known under several names. In Europe it came out as UFO: Enemy Unknown and in North America as X-COM: UFO Defense; the North American demo used the working title X-COM: Terran Defense Force, and a 1996 re-release was called X-COM: Unknown Terror. Amiga versions appeared in early 1994, and PlayStation versions followed in 1995.
IGN named it the best PC game of all time in 2000 and again in 2007. The open-source OpenXcom, a C++/SDL clone that requires the original data files, keeps the game playable on modern systems.12
Names and releases
| Region | Title on the box | Platform | Date | Publisher | Src |
|---|---|---|---|---|---|
| NA | X-COM: UFO Defense | MS-DOS | May 1994 | MicroProse | 1 |
| NA | X-COM: UFO Defense | PlayStation | October 1995 | MicroProse | 1 |
| NA | X-COM Collector's EditionWindows Collector's Edition re-release. | Windows | 1998 | MicroProse | 1 |
| EU | UFO: Enemy UnknownRussian Wikipedia gives 31 December 1993; English Wikipedia says the PC version was completed in March 1994. | MS-DOS | March 1994 | MicroProse | 1 |
| EU | UFO: Enemy UnknownEarly 1994; OCS/ECS and AGA versions, plus a CD32 version. | Amiga | 1994 | MicroProse | 1 |
| EU | X-COM: Enemy Unknown | PlayStation | November 1995 | MicroProse | 1 |
| WW | X-COM: UFO DefenseSteam release; also part of X-COM: Complete Pack. | Windows | Sep 4, 2008 | 2K | 3 |
Also known as: UFO: Enemy Unknown EU1X-COM: Enemy Unknown EU1X-COM: Terran Defense Force NA1X-COM 未知なる侵略者 JP1X-COM Michi Naru Shinryakusha JP1Команда Икс: Защита от НЛО RU4НЛО: Враг неизвестен RU4X-COM: Unknown Terror WW1
Box art by region
EU UFO: Enemy Unknown
Box art © its publishers, shown to identify each release. Scans: Wikipedia.
Version differences
-
AudioPS1
The PlayStation version swaps the PC's MIDI soundtrack for CD-quality music by Allister Brimble and adds 3D models to the UFOpaedia.1
-
ContentPS1
The ending differs: on PC the aliens poison the planet, while on PlayStation they kill the negotiator.1
-
GraphicsAmiga OCS/ECS
The Amiga OCS/ECS version has lower-quality graphics and no light-source shading in combat but better sound; the AGA and CD32 versions have improved graphics.1
Translations
-
Spanish Fan
—MS-DOSReleased
PCGamingWiki lists a fan-made Spanish translation patch.5
Where to play legally today
-
Steam Purchase
How to run it today
Buy the game on Steam, on its own or in the X-COM: Complete Pack; digital versions come pre-patched to version 1.4. According to PCGamingWiki, the DOS version runs through DOSBox, while the Windows Collector's Edition runs natively but has its own bugs. The most comfortable option on modern Windows is OpenXcom, an open-source reimplementation that needs the original game's data files (its Windows installer can copy them from a Steam installation) and also runs on macOS and Linux. For the original executables, XcomUtil fixes the difficulty bug and other issues.
- OpenXcom on GitHub github.com
- PCGamingWiki: X-COM: UFO Defense pcgamingwiki.com
Best version
PCGamingWiki calls the open-source OpenXcom engine an essential improvement: it removes the need for DOSBox, fixes almost every major bug and adds unlimited saves and widescreen support.5
Reception
GameRankings averages were 94% for PC and 93% for PlayStation, and Computer Gaming World gave it its Game of the Year award. It sold over 600,000 units on DOS, and together with its sequel passed one million by March 1997.1
In lists
Sources
Checked: 2026-10-13Text reviewed: 2026-10-13
Spotted a mistake? Write to atlas@old-games.net.