X-COM: UFO Defense, X-COM: Terror From the Deep, X-COM: Apocalypse, X-COM: Interceptor and X-COM: Enforcer are now available on Steam for $4.99 each, or in a package deal that includes all five titles for $14.99. Valve is marking the Steam debut of the great X-COM series by offering an additional ten percent off the prices during the first week of release, and while Windows Vista is not officially supported by the games, this post in the Steam forums says all five titles have been tested under Vista and run without problems.
The X-COM games debuted in 1993 with X-COM: UFO Defense (known as X-COM: Enemy Unknown in Europe), a tactical combat game that also offered strategic elements, research trees, statistical character development and more. Many elements of the game, including spaceships and aliens, were designed after classic 60s and 70s movies and television shows about alien invasions.
X-COM: UFO Defense is far and away the best game of the series, and with X-COM: Interceptor the franchise moved away from its tactical roots, becoming a space combat simulator instead. But Interceptor sold poorly, and despite its early successes the X-COM title slowly faded into obscurity, a fate sealed when Hasbro Interactive, which had purchased original X-COM publisher Microprose, was shut down by Hasbro. Rights to the property then passed to Infogrames by way of Atari before landing with Take-Two Interactive, where BioShock designer Ken Levine is rumored to be working on a new addition to the series.
And while he's playing around with that, you could be playing around with the entire X-COM franchise for 15 bucks. There's a lot I don't particularly care for about Steam, but this is a screaming good deal. The game is deep, accessible even to fans who wouldn't normally consider something called a "tactical combat simulator," and unless you happen to be reading this on a 286 with less than four megabytes of RAM, you have zero worries about system requirements. X-COM: UFO Defense is widely regarded as one of the finest games ever made, and you can have the whole thing for 15 bucks! So why are you still reading this?