XCOM: Enemy Unknown achievements

In a single game, complete every Autopsy.

Kill an enemy as it is psionically attacking you.

Complete a Very Difficult abduction mission in five turns or less on Classic or Impossible difficulty.

Kill an unseen enemy detected by a specially modified soldier.

Beat the game on Classic difficulty.

Play a multiplayer match against someone with this achievement.

In a single game, complete every Research Project.

Complete Confounding Light with more than 3 turns left on the timer.

Take your new ally into the final challenge.

Field a fully enhanced squad and win the mission

Have your special-duty soldier kill three enemies in the same mission

Kill a Muton Berserker in melee combat.