UFO: Enemy Unknown - Reception

Reception

The game was released to very positive reviews and commercial success, selling more than 600,000 units on the PC DOS platform, not counting the later ports—for the Amiga platforms and the PlayStation—and re-releases. Half of the game's net sales were in the United States, a rarity for a European title at the time. Gollop has attributed the game's North American success to its title (X-COM), as the television series The X-Files had premiered a year earlier.

According to a 1996 review by GameSpot, "Put simply, X-COM is a bona fide modern classic, standing proudly alongside Civilization and Populous as a benchmark in the evolution of strategy gaming." A 1996 review of the PlayStation version by Electronic Gaming Monthly stated that "any person who likes strategy games will fall in love with this title," adding: "If you could afford to buy one game for the PS over the next year, X-COM would be it. It has it all and then some!" Computer Gaming World gave it its Game of the Year award for 1994. In 2009, Edge called it "the title that first brought turn-based wargaming to the masses."

Amiga ports received lower ratings than the PC original (which holds an average score of 93.60% at GameRankings), according to Amiga HOL database having averaged scores of 79% on the ECS/OCS Amigas, 82% on the AGA Amigas and 73% for the Amiga CD32 version. A common point of criticism for the floppy disk version was the need to frequently swap the disks in the Amiga systems not equipped with a hard disk drive, while the CD-ROM CD32 version does not allow the users to save progress of any other game without wiping out the save game of UFO. Nevertheless, a review in Amiga Action called it "easily the most original and innovative game in the history of the Amiga", a review in Amiga World called in "the shortest path to heaven" for a strategy gamer, and a review in CU Amiga of the 1997 budget range re-release called it "game everyone loves." In 2011, Polish web portal Wirtualna Polska ranked it as the 13th best Amiga game.

Since its release, the first X-COM has often appeared in top video game lists by various publications:

• IGN named it as the number one top PC game of all time in 2000 ("the finest PC game we have ever played") and 2007 ("there's still no PC game that can compete with the mighty X-COM"), as well as ranking it as the second top "modern PC game" in 2009. IGN also included it on several lists of the best video games of all time on all platforms, including at eight place in 2003 ("a game that will live on in the annals of computer gaming history"), at 12th place in 2005 ("for us 1994 will always be remembered as the year of X-COM"), and at 21st place in 2007 ("one of the most memorable and perfectly executed strategy games ever seen").
• Computer Gaming World (CGW) ranked it as the 22nd (1996) and third (2001) best computer game of all time. The magazine's readers also voted it for tenth place in 2001.
• PC Gamer ranked it as the seventh (1997), third (2001), eight (2005), tenth (2007 and 2008, calling it a "truly groundbreaking game" that "still plays fresher than almost anything else that begs passage through these pages"), 11th (2010, the editors adding that everyone who would not vote for this game is "dead" to them) and 12th (2011, describing it as "brilliant game ... whose individual elements have been copied many times but whose charm has never been duplicated") best PC game of all time. It was also voted 15th by readers in 2000.
• X-COM/UFO has been ranked as the 35th best video game of all time by GameSpy in 2001 ("stellar game design can withstand the test of time"), as the second best video game since 1992 by Finnish magazine Pelit in 2007, and as the 78th best video game "to play today" by Edge in 2009.

It was also inducted into several hall of fame type articles, including by CGW in 2005 ("a great game which proves that pushing the technological envelope is often less important than stoking the gamer's competitive fire"), by GameSpot in 2003 (featured in The Greatest Games of all Time as "one of the defining games of the turn-based strategy genre"), and by IGN in 2007 ("if this game were a woman, we'd marry it").

In 1996, CGW ranked it as the number one sleeper hit of all time. In 1999, the game's Xenomorph-inspired alien race of Chryssalids was ranked as fourth on the list of best monsters in gaming by GameSpot, where X-COM was also called "one of the scariest computer games ever." In 2012, The Escapist ran a feature article about "why X-COM is the greatest game ever," UGO.com described it "a perennial 'best game ever' contender," Ken Levine of Irrational Games named it as one of his all-time personal favourites, and 1UP.com ranked it as the 90th most essential game of all time, commenting that "with its unrivaled balance of tactics and tension, XCOM remains a masterpiece."