Easter Eggs (XCOM: Enemy Unknown)

Easter Eggs are intentionally hidden messages, jokes, or features in XCOM: Enemy Unknown.

X-COM Arcade Game

The "X-COM Fighter Alpha" arcade game can be found in the Barracks facility in XCOM Headquarters and on the Bar map available in multiplayer or as a Terror Site mission. It features images of a soldier and a Sectoid from the original UFO: Enemy Unknown/X-COM: UFO Defense game.

Bradford's Commentary

While visiting the Situation Room, the comments Central Officer Bradford makes occasionally include hidden references:

• "We've been picking up some odd transmissions lately... some nut calling himself 'Commander Straker' has been all over the news ranting about shadow operatives."
  This is a reference to Commander E. Straker and the SHADO agency from the 1970 UFO (TV series).
• "This is Central, I'm receiving you... what do you mean you think you saw a snake? What the hell does that have to do with anything?"
  This is likely a reference to Snakemen, a species of alien from the original X-Com that was left out in this remake.
• "Are you really using your console to play Civilization?... At least I hope you are trying to achieve the Military Victory..."
  This is a reference to Sid Meier's Civilization V, the other game that Firaxis was developing at the same time as XCOM: Enemy Unknown.
• "...and you are positive that an UFO crash landed in the low-downtown house backyard of a middle-class family... the Tanner residence. Roger, looking into it."
  This is a reference to the TV sitcom ALF from the 1980s.
• "Don't patch that through - No....we're here to track alien activity, not investigate haunted houses."
  This comment is added in XCOM: Enemy Within and is a reference to the iOS game Haunted Hollow released by Firaxis.
• "I don't want to hear anything else about forming an ace patrol... we don't have time for alien dogfights."
  This comment is added in XCOM: Enemy Within and is a reference to the game Sid Meier's Ace Patrol also by Firaxis.

Soldier Commentary

The comments made by soldiers during battle also occasionally include hidden references:

• When successfully using the Arc Thrower against an enemy, a soldier may comment with:
  • "1.21 gigawatts baby!"  A clear reference to the film Back to the Future as this is the amount of energy required to operate the Delorean time machine.
  •  "Ride the Lightning." A reference to the band Metallica, whose second released album had this name. 

Research Reports

The reports reports that players can read after the completion of the research projects include several hidden references and themes:

• Chryssalid Autopsy: Codename Ripley
  Reference to the heroine of the Alien films, Ellen Louise Ripley.
• Ethereal Device: "A team of brothers have already conceived of just such a facility."
  The Gollop Chamber owes its name to the Gollop brothers, developers of the original game.
• Floater Autopsy: Codename Crimson Cape
  Reference to the Floaters in the original game, who wear red capes.
• Hyperwave Communication: Codename Tachyon
  Reference to a type of particle in the original game.
• Outsider Shard: Codename Novato
  Reference to the location of 2K Games headquarters in Novato, California.
• Seeker Autopsy: Codename Lovecraft
  Reference to Howard Phillips Lovecraft, horror fiction writer, creator of the Cthulhu Mythos.
• Thin Man Autopsy: Codename Viperus
  Reference to the Snakeman alien in the original game (a Viper is a poisonous snake).
• Several research project codenames are a species of bird:

Alloy Cannon: Codename Avocet	Plasma Rifle: Codename Kestral
Heavy Plasma: Codename Kingfisher	Plasma Sniper: Codename Osprey
Light Plasma Rifle: Codename Corvid	Sectopod Autopsy: Codename Halcyon
Plasma Pistol: Codename Jacamar

Caution Signs

Funny warning signs can be found in both the Engineering and Satellite Uplink facilities.

Research Labs

On the right most wall of the Research Labs facility the serial code OG 1994 is printed. This is likely a reference to the 1994 release date of the original game.

Test Firing Targets

After being built for the first time, both the Laser Rifle and Plasma Rifle each feature a test firing cinematic where the target is an the image of an alien from the original game; a Sectoid and a Muton (respectively).

Hidden Bases

During the cinematic following shooting down the first UFO, the recon satellite imagery of the crash site displays a set of  Latitude and Longitude coordinates (N 38 3.59562 W 122 30.958157) which correspond with the 2K Games Corporate Office in California.

During the cinematic where the Alien Base is revealed, the recon satellite imagery of the base displays a set of Latitude and Longitude coordinates (N 39 31' 16.68 W 76 38' 46.82) which correspond with the Firaxis Games studio in Maryland.

XCOM Heroes

When renaming your Soldiers, entering certain names will unlock "hero" characters with extraordinarily high stats and advanced equipment load outs. Activating any of these characters disables Trophies/Achievements for that game.

XCOM: Enemy Within

Inside the new bank map is a picture of Garth DeAngelis alongside presumably some of the bank founders.

During the Site Recon mission in Newfoundland, Bradford will comment on the crashed whaling ship stating "... at least it wasn't a cruise ship" and the after mission report mentioning alien interest in infesting marine life: A subtle nod to the infamous terror missions of X-COM: Terror From the Deep and the game itself respectively.

The Bureau References

The expansion also includes several nods to The Bureau: XCOM Declassified.

• A fedora makes an appearance as a new helmet/hair option available to soldiers.

• Meld Recombination's project report contains a reference to "redacted data stores created in the 1960s".

• Renaming a soldier "William Carter" unlocks a new XCOM Hero.