Originally released in the UK as UFO: Enemy Unknown, X-COM: UFO Defense combines challenging turn-based gameplay with base building, research management, and persistent squad members. Throughout the game, players will encounter five alien races all intent on subjugating the people of Earth. The Extraterrestrial Combat Unit must prevent this from happening by tracking and shooting down UFOs, stopping terror attacks on major cities, and eliminating alien bases before they can infiltrate governments across the world.
Bases, workers and squad destinations are managed in the Geoscape view, before switching to the battlescape view for missions.
Troops sent on missions improve with the actions they take and can individually be equipped with a variety of firearms and grenades. Upon elimination of all the aliens on the battlescape, your units will return alien artifacts to your base, where you can assign your scientists to start researching different weapons and technology. New weapons, gadgets, and aircrafts can be manufactured by your engineers, adding toys like medpacks, hover tanks, and plasma weapons to your arsenal.
UFO: Enemy Unknown was originally conceived as a sequel to Laser Squad, another game by Julian Gollop.
Shooting down UFOs will allow your transport ship to land at the crash site, and your troops will be tasked with eliminating any surviving aliens. All missions play out in turns, with the player always going first. Troops have Action Points that are depleted by everything from moving and shooting to turning and priming grenades.
Alien weaponry is far superior to your troop's early rifles and heavy cannons, requiring caution and overlapping movement to keep squad members alive. A sort of overwatch allows soldiers to save action points for the alien turn, and, depending on an individual's Reaction stat, he or she may fire on an alien that moves into line of sight. UFOs may also land, supposedly to abduct people or cattle, or just to do some Earthly research of their own, and your transport ships can catch the aliens off guard. Research rewards are often better, as the UFO itself is not damaged like when your Interceptors shoot them down. However, this also means that there will be more aliens to contend with on the ground.
Terror missions are arguably the most difficult, as they occur at inopportune times around the world and last only a few game days, leaving little time to prepare before the city is ransacked. Failing or ignoring these missions will make the local government unhappy, which might lead to funding cuts at the end of the month. In Terror missions, the aliens set out to kill as many civilians as possible, so your job is to protect the citizens by quelling the alien threat as quickly as possible.
Aliens also will try to construct bases on Earth, as evidenced by heavy UFO activity in certain countries (a month by month stat page can help highlight this sort of information). These missions are completed by killing or capturing all aliens inside. It is worth noting that at the core of the bases, a high-ranking alien can usually be found who will yield valuable information if taken alive and interrogated.
The world map progresses with time, and missions can be taken during night or day. All the aliens have the unique advantage of seeing just as well at night as you do during the day, making Terror missions an absolute nightmare during the evening hours.
There are five alien races, each with an associated support unit, usually only seen on the Terror missions or within their bases.
The Sectoids are based on the bug-eyed grays so common in extraterrestrial movies, shows, and games. They pair with Cyberdiscs - mini UFOs that hover and shoot, but explode when destroyed.
The aptly named Snakemen are physically tough units that team up with the terrifying Chryssalids, fast moving bipedal insects that turn their victims into zombies, which can then turn into more Chryssalids.
The crafty Floaters have no legs, and instead, well, float around and guide their giant just-legs-and-a-mouth accomplices, the Reapers.
The iconic purple and green Mutons, who couple with Celatids - purple floating kidneys that shoot acid at your troops. Seriously. They're also accompanied by Silacoids, which are essentially big moving rocks.
The orange robed Ethereals have the strongest psychic powers, and have basically a mechanized form of the Reaper for their Terror missions called Sectopods.
Construction of multiple bases is critical to later success, though funding and management of multiple bases provides it's own challenge. You must hire and pay all personnel and also pay upkeep for your various facilities on a monthly basis. Radar systems, storage areas, living quarters, and research and manufacturing areas must be constructed to accommodate your alien hunting ventures. Later, base defenses, alien containment, and more hangar space become important to your mission. Management of weapons and ammunition for troops and ships also occurs here.
Should your base be invaded by hostile forces you will have to defend yourself within the base you have constructed. Aliens will infiltrate through possible entry zones, like gun ports and hangars. Supplies that you don't allocate to the team that happens to be there to defend the base will be in storage areas, and not all of the base is well-lit (read: hangars), making visibility a problem. It is difficult to build a base defensively, and invasions can often be devastating if you're not ready for them (including losing your base as a consequence if you lose the fight), so it's best to guard against invasions by putting up strong defensive weapons and other defenses you learn about later in the game, as well as having some defenders at the base in case of attack, especially in the later levels.
Research & Development
Hiring and utilizing scientists and engineers allows progress in the game, both technologically and story-wise. More powerful and varied weapons are made available, as well as personal armor, building types, and information about the aliens. Psychic research also becomes part of the gameplay, allowing your troops to use the alien's mind control and terrifying abilities against them. The later aircraft are necessary for completing the game, and only by bringing in live aliens will your scientists discover a way to eradicate the alien menace. Learning new things opens up new avenues of research, propelling you toward having the tools to bring about the conclusion-- as long as you allocate enough scientists to the task.
When pursuing enemy craft with your aircraft on the Geoscape, you may get within firing range. This spawns an intercept minigame which pits your craft against the UFO. Smaller UFOs tend to be more fragile and less heavily armed, while the top of the line enemy ships can easily wipe out your aircraft, especially if the aircraft's armament doesn't have sufficient range to afford to stay away. When at a stand-off distance, you can actually minimize this pursuit to manage other onscreen events (like other pursuit craft). The button for this is in the upper right corner of the pop-up. In older versions, this would sometimes lead to a crash.
In the screen to the left, you see the pop-up box that connotes the intercept mode. The green-colored field to the far left of the pop-up visualizes your distance to your target, and the range and ammunition that your weapons have. The four upper-right buttons are your approach tactics (clockwise from upper left):
- Standoff (maintain maximum distance but continue pursuit)
- Long distance attack (fires at a low rate of fire and at maximum possible distance)
- Moderate attack (fires all weapons at minimum necessary distance)
- Point blank (charge right at the enemy vehicle, weapons blazing. This increases damage potential but puts the interceptor at greater risk)
The silhouette of your craft shows the percentage of damage that your craft has taken shown by glowing red, starting from the tip and working its way to the back.
The final two buttons are retreat, and visualize enemy. The former simply disengages your craft, which flies back to base. The latter shows you what the craft you're pursuing looks like, helping you to identify it if its size class isn't enough. As you learn more about the enemy craft, these UFO types will become more familiar.
Finally, there is a numerical distance rating that corresponds to the representation on the left.
Should your craft be able to land and deploy troops, and you force the enemy to crash-land or it lands on its own, you will instantly land and begin a ground mission. It's also possible that the enemy could run away, destroy your craft, cause you to retreat, or be completely destroyed by your weaponry or by crashing into the sea.
- Supported OS: Microsoft® 2000/XP/Vista®
- Processor: 80386 processor or better
- Memory: 4Mb RAM
- Sound Cards Supported: AdLib compatible cards, SoundBlaster compatible cards and the Roland LAPC