The XCOM series first game was XCOM: Enemy Unknown released on 9th October 2012.
2012
XCOM: Enemy Unknown
9th October 2012
2013
The Bureau: XCOM Declassified
6th August 2013
23rd August 2013
2016
XCOM: Enemy Unknown Plus
22nd March 2016
XCOM 2
6th September 2016
27th September 2016
2020
XCOM 2 Collection
29th May 2020