The follow-up to the strategy Game X.C.O.M.: Enemy Unknown, which won Game of the Year in 2012, is titled X.C.O.M.: Enemy Within. 

Enemy Within provides an astounding variety of new skills, upgrades, and weaponry to tackle brand-new enemies and extraterrestrial dangers. 

Additionally, this expansion adds new multiplayer content, new tactical and strategic gameplay, and new locations and objectives for an entirely new gameplay experience.

Key Features

• Build the Cybernetics Lab to enable the creation of the new Mechanized Exoskeletal Cybersuit, M.E.C., or the Genetics Lab to increase your operatives' powers, including augmentations to the chest, brain, eyes, skin, and legs. Specialized skills are available to the new M.E.C. Trooper class, and they may upgrade each suit with brand-new weaponry like the flamethrower and grenade launcher.
• New Armaments and Gear With fresh initiatives from your engineering team and the Foundry, you may give your operatives a tactical advantage.
• Adapt innovative strategies to combat the challenges posed by two new alien kinds and the lethal new organization known as EXALT.
• New Strategic Resource: Meld, a priceless new alien resource, has been found. To get new research and upgrades, safeguard it on the battlefield and use it judiciously once you're back at base.
• New tactical difficulties and maps: On more than 40 new battlefields, cloak-and-dagger and intelligence operations provide new tactical challenges.
• Maps, units, and abilities for multiplayer:Intense, one-on-one, turn-based contests allow you to dominate your opponent by building your bespoke squad from a more extensive selection of alternatives.
• For the single-player Game, 47 additional maps have been added, bringing the total number of maps to well over 120. In addition to the five already present multiplayer maps, eight additional ones have been added, making a total of 13 multiplayer maps.
• Alternatively, we can alter them into the brand-new class "M.E.C. Trooper," which is capable of using Mechanized Exoskeleton Cybersuits in battle. However, because the cybernetic modification includes amputation of all four limbs, they cannot engage in combat without a M.E.C. 
• Large bipedal combat platforms with a cyborg pilot in their upper torso, M.E.C.s are more durable, better equipped, and mobile than regular operators despite being astronomically expensive to deploy and upgrade. 
• Additionally, the Super Heavy Infantry Vehicle, or S.H.I.V., combat robots used by X.C.O.M. acquire improvements.
• The Seeker is an aerial machine that resembles a Squid and is equipped with a cloaking system and a plasma blast as its main armament. Cloaking is a temporary state that eventually wears off. It can utilize its Strangle ability while cloaked if it approaches a lone X.C.O.M. agent. 
• It typically shows up in pairs and will cloak if it is seen. Their A.I. will stay out of the way of X.C.O.M. forces and hide until the soldiers battle another set of aliens. When the opportunity arises, the Seeker strikes, sneaking up on a lone human target and activating the strangle ability.