XCOM Enemy Unknown, tactical pose, squad-based, alien invasion, futuristic weapons, urban environment, destructible cover, strategic map, base management, soldier customization, permadeath, cinematic camera angles, dramatic lighting, intense atmosphere, science fiction, turn-based combat, extraterrestrial enemies, Skyranger dropship, research and development, international council, panic levels, satellite coverage, interceptor aircraft, full-body armor, plasma rifles, Sectoid alien, Chryssalid terror, Ethereal mastermind, final boss battle, Temple Ship assault, heroic victory pose, Commander's office, ant farm base structure, global defense. XCOM Enemy Within, MEC Trooper, genetic modifications, new enemy types, EXALT faction, covert operations, expanded customization, new maps, meld resource, cybernetic augmentation, Seeker stealth unit, Mechtoid enemy, tactical rigging, new medals and awards, base defense mission, new soldier abilities, enhanced strategy layer, alien abduction, council missions, terror attacks, Progeny and Slingshot DLC missions, Operation Progeny, Operation Slingshot, new strategic resources, enhanced soldier progression, alien invasion expansion, integrated tutorial, adaptive war tactics, expanded headquarters, XCOM medals of honor, alien containment facility, Sectopod redesign, Ethereal mind control, cinematic action sequences, dynamic combat music, enhanced soldier dialogue, interactive mission briefings.