It's canon. We lost the fight in XCOM: Enemy Unknown. The sequel takes place 20 years after the unconditional surrender of human forces to the alien threat, and after the aliens have enforced their iron fisted rule over humanity. On the fringe outskirts, beyond the cities, a handful of renegades have organized to fight back, dusting off the old title of humanity's defenders. XCOM is back.

The trailer shows that Snakemen have finally returned, and that standard units can apparently use melee attacks. Other interesting news we've gotten is an announced fifth class, confirmation of more customization (including being able to choose gender and nationality), the ability to surprise aliens and hit them before they scurry to cover, and probably more that I've missed.

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