UFO: Aftermath

Rooted deeply in the X-COM series, the game combines elements of strategy with squad-based tactics. The game consists of two alternating phases: a strategy phase in which players control and expand their organization, and a tactical phase in which player-controlled units battle alien enemies.

The strategic phase allows players to equip and train their troopers for action, acquire new equipment and personnel, send fighter planes to intercept UFOs, and conduct research to enable the production of more advanced equipment. Mission markers pop up on the globe, indicating locations where a team can be dispatched to battle. Players may expand their territory by capturing bases, allowing more access to resources. Initially, each base can be freely changed to a military, research, or engineering base to suit the player's needs. As the game progresses, the player will also have to contend with ever-growing bodies of biomass that will consume their bases and must be stopped with specialized anti-biomass bases.

In May 2004, a giant spacecraft approached Earth. Hovering over the planet and ignoring all human attempts at contact, it released large clouds of spores into the upper atmosphere. Rapidly multiplying, the spores soon darkened the skies, obscuring the sun completely. This period became known as the "Twilight".

After having reached critical mass in the skies, the spores began to rain down, clogging the streets and bodies of water, smothering people in their homes and burying animals in the wild. During the "Nightfall", as it would come to be called, most of the higher life forms on earth were wiped out. During these events, all human responses were futile. The governments of the world chose caution over aggression, not realizing how quickly the end could come, and were buried.

Originally, the game began as an abortive project titled The Dreamland Chronicles: Freedom Ridge by the British company Mythos Games, headed by the original creator of the X-COM series, Julian Gollop. Following the bankruptcy of Mythos, the unfinished game was bought from Virgin Interactive by the Czech company Altar Interactive in 2002. However, disappointed with the state of development, and finding themselves unable to simply complete it, Altar soon decided to restart it almost completely, retaining only some of the original project's core concepts and ideas but practically none of its actual assets, featuring a completely different combat system and a largely new story. Even the game's title changed, first to UFO: Freedom Ridge and finally to UFO: Aftermath.

UFO: Aftermath received middling reviews. GameSpot gave it 6.4 out of 10 for some simplified and missing features, previously seen in X-COM, that would have allowed for more in-depth gameplay. IGN gave it 7.5 (Good), criticizing simplicity and lack of some features from the X-COM series. GameSpy noted: "Cons: Bad AI and pathfinding; repetitive missions; shallow strategic gameplay; persistent inventory bugs," but praised some parts of the game.

Both official and third-party tools exist to help modding UFO: Aftermath. In order to encourage user mods, the publisher held an official contest, resulting in mods affecting many aspects of the game, including skins, weapon models, and characters. The tools are also compatible with the first sequel, UFO: Aftershock. The third sequel, UFO: Afterlight, will not accept modded content or added content because of changes in its engine.