XCOM Enemy Within was announced on August 21st, 2013, with a release date of November 12th that year. It is a expansion pack to XCOM Enemy Unknown. Enemy Within featured the same story progress of the same invasion from Enemy Unknown, but added more features, units, abilities, resources, and maps. In an interview, Garth Deangelis, producer on Enemy Within, said that the expansion could be seen as a 'Director's Cut' to Enemy Unknown.
The game is DLC on PC and Mac, meaning the player needs Enemy Unknown in addition to Enemy Within to play. For Xbox 360 and PlayStation 3, it is a standalone game that is bundled with the 'Elite Soldier Pack', DLC that enables players to further customize units; and 'Slingshot', a set of three unique Council Missions that feature a special soldier.
Enemy Within includes 'Operation Progeny', a content pack similar to the Slingshot DLC. It was originally planned to release for Enemy Unknown separately, but withheld due to Slingshot's poor fan reception. It can be activated or left alone in Enemy Within, similar to Slingshot.
Enemy Within adds a much requested feature, which is the ability to let operatives speak in their native languages. The player can customize any soldier to speak in any language in the game: English, French, Italian, German, Spanish, Russian, and Polish. The aim of this feature is to have XCOM be more clearly about a multi-national operation, whereas in Enemy Unknown all soldiers spoke American English.
Enemy Within features new units on both the XCOM side as well as the Alien faction. XCOM has a new class in addition to the preexisting Assault, Support, Heavy and Sniper called the MEC trooper (Mechanized Exoskeleton Cybersuit). MEC troopers are large mech-type soldiers that still take up the same space (one tile) as all other soldiers. Any soldier, except Rookies, can be turned into MEC troopers, provided players have sufficient resources to create them. The soldier loses all their abilities in their current class when they are transformed into a MEC trooper, but retain their rank. MEC troopers also inherit an ability depending on the class they were before they became a MEC trooper.
MEC units employ a variety of new abilities as well as inherent high health. Choices must be made how the player wants to equip their MEC trooper. Some of the choices are between a flamethrower, which does 6 damage in a cone in front of the trooper; Kinetic Strike Module, which does 12 damage to a target in close range; Grenade Launcher, which allows grenades to be fired much further than when thrown; Restorative Mist, which heals multiple squad mates; Electropulse, which is an area of effect attack for damage and stunning robotic units; and Proximity Mines.
MEC troopers can also use an ability called Collateral Damage, which is a much asked about feature since Enemy Unknown has been released. It allows the unit to fire with the intent of breaking down cover at a very high ammo consumption rate. MEC troopers can also provide full cover for squad mates by activating One for All. Moving, firing or using abilities will negate the cover.
MEC troopers require a new structure, the Cybernetics Lab, to be build.
Enemy Within allows players to enhance their soldiers effectiveness using gene mods. Unlike the MEC trooper, gene mod soldiers retain their previous class. Any soldier can become a gene mod soldier with the exception of MEC troopers, provided the player has sufficient resources to augment them. Also unlike MEC troopers, gene mod soldiers can be tested for psionics and if they are gifted, the psionics will stack with their gene mod abilities. Gene mod soldiers feature sleeveless armor to differentiate them easily from other soldiers, but this is only a visual change to otherwise similar armor.
Gene mods can be applied to the brain, eyes, chest, skin and legs. Similar to class abilities, each category can only have one active ability at a time. Players can have one ability in all categories, but never two abilities in one category. Some of the abilities include Boosted Muscle Fiber, which allow soldiers to jump up on buildings and rooftops without having to use conventional methods to get there. Mimetic Skin lets the soldier become invisible if they end their turn in high cover (and weren't seen by the enemy moving there). Neural Feedback allows the soldier to damage any alien trying to mind-control it. Neural Damping makes the soldier immune to panic and instead of being mind-controlled, it will pass out for 1 turn instead. There even is a mod that protects the soldier from perma-death by adding a second heart.
Gene mod soldiers require a new structure, the Genetics Lab, in order to be augmented.
There are several new alien types in Enemy Within. Only two new alien types are announced so far. The Mechtoid and the Seeker. The Mechtoid is a Sectoid in a exoskeleton suit, similar to the XCOM MEC troopers. Some of its abilities include being able to fire twice in one turn (provided they do not move) and going on Overwatch as soon as they are discovered by the player. Mechtoids feature high health and Sectoids can Mind Merge with them, providing the Mechtoid with additional shielded health. Killing the Sectoid in this progress does not kill the Mechtoid as it does when two Sectoids merge, but merely removes the shielded health.
The Seeker is a robotic tentacle unit. On its first turn after being discovered, it activates stealth-mode, letting it become invisible. It will only become visible again when it attacks, although the player has options to make it visible before then. Using Bio-electric Skin, a gene mod, for instance. Seekers, when attacking, strangle their target causing damage over time each turn. The damage they inflict increases with each passing turn. Their target is incapable of taking action when being strangled. The Seeker must be eliminated by another team member. When destroyed, the recipient of the strangle attack must take a turn to catch their breath. Seekers try to seek out lone targets, effectively becoming a threat to the much used Squad Sight Sniper.
A new resource has been introduced into Enemy Within, called Meld. Meld is a resource that can be acquired by reclaiming it from the battlefield before the tanks that contain them, explode. A timer will reveal how many turns are remaining before the Meld is lost, trying to encourage players to play less conservatively and take more risks. Meld is required for both the MEC trooper and gene mod soldiers. For instance, each gene mod the player wants to apply to a gene mod soldiers costs a certain amount of Meld.
Missions and Maps
Enemy Within features new mission modes that are currently not yet revealed.
47 new maps have been added for the single player game, adding to the existing 80 maps bringing the total to well over 120 maps. Eight new multiplayer maps have also been added to the existing five, bringing the total to 12 multiplayer maps.
Most notably, scenery can be quite different from the standard locals visited in Enemy Unknown. Some maps take place on a abandoned farm, others on top of a water dam, as opposed to the standard city and forest maps.
When first playing the game, it will offer more of the new maps rather than existing Enemy Unknown maps. As the playthrough progresses, this will even out. Eventually, any subsequent playthrough will feature as much new as old maps. The older maps have been tweaked to also contain the Meld resource on them.
Enemy Within received some balancing tweaks that were implemented either because they didn't work well with the new content or they were complaints by fans of the game. Some of the balancing include the following:
- Squad Sight balance: hitting an alien outside of the sniper's own view will no longer grant a chance of a critical hit, unless the sniper uses the ability Headshot.
- Snap Shot balance: the aim penalty for using Snap Shot has been reduced to -10 aim as opposed to the previous -20 aim.
- HEAT Ammo balance: has been decreased to +50% damage to robotic enemies, as opposed to +100% damage.
- Deep Pockets: since the new Foundry upgrade 'Tactical Rigging' will provide 2 item slots for all squad members, Deep Pockets has been changed to adding a charge to every use item (example: Arc Thrower will have 3 uses instead of 2, grenade will have 2 uses instead of 1, MediKit in relation with Field Medic will have 4 uses instead of 3 and so on).
- Covering Fire balance: will now trigger before the enemy shoots as opposed to triggering after the enemy shoots.
- Close and Personal: reworked to Up Close and Personal, providing a free shot in close proximity of an enemy that does not cost an action point (different from Close Combat Specialist in that it can be used on the player's turn, whereas Close Combat Specialist is a reaction shot).
- Sectopod: received a buff to distinguish it as a superior unit from the new Mechtoid.
- Panic will be less likely to cause soldiers to fire on friendly troops and more likely to destroy the environment. The panicked soldier also suffers an aim penalty.
- Weapons and items will be more easily accessed when selecting squad load out by having anyone not in the squad selection automatically dump their equipment in the pool.
- The game will be easier on both Easy and Normal than in Enemy Unknown, due to the new technology available. The game will be more challenging on Classic and Impossible due to added time requirements for research and promotions as well as more use of new challenging enemy types.
- Bugs have been addressed. Most notably, the 'flanking bug' has been claimed to have been removed entirely and the 'teleport bug' has similarly been addressed.