Firaxis Games and 2K Games released XCOM: Enemy Within as an expansion pack to XCOM: Enemy Unknown, adding new content and features to the base game.
Firaxis Games announced the development of XCOM: Enemy Within, detailing upcoming features including new soldier abilities, enemies, and strategic elements.
The covert paramilitary organization EXALT manages to stay hidden from the XCOM project, undermining its efforts.
XCOM begins integration of MEC Troopers, soldiers augmented with mechanized exoskeletons enhancing combat capabilities.
XCOM develops genetic modification techniques to create gene soldiers with enhanced physical abilities and psychic powers.
EXALT launches direct attacks on XCOM facilities to steal resources and technology, exposing their existence.
XCOM arms its soldiers with arc throwers to capture live remaining alien specimens for research purposes.
Alien forces increase attacks worldwide, forcing XCOM into a state of heightened alert and rapid response.
XCOM successfully captures and dismantles EXALT's command structure, weakening their operations significantly.
XCOM launches an assault on the alien base to stop the Ethereal leaders and halt their invasion plans.
