Build an item.
Complete a Research Project.
Complete a mission without losing a soldier.
Complete the tutorial mission.
Build a base facility.
Shoot down a UFO.
Launch a Satellite.
Beat the game in Ironman mode on Classic or Impossible difficulty.
Win a multiplayer match.
Mind Control an Ethereal. Single player only.
Beat the game on any difficulty.
Beat the game on Classic difficulty.
Beat the game on Impossible difficulty.
Clear a UFO crash site with one soldier on Classic or Impossible difficulty.
Kill 50 aliens with explosive weapons.
Kill 150 aliens.
Kill 500 aliens.
Shoot down 40 UFOs.
Have a soldier survive every mission in a full game.
Earn the "Excellent" rating in every performance category on a terror mission.
In a single game, complete every Research Project.
Kill an alien while flying. Single player only.
In a single game, complete every Autopsy.
Find a soldier with the Gift.
Capture a live alien.
Stun an Outsider.
Uncover the alien base's location.
Build the Hyperwave Relay.
Build the Gollop Chamber.
Build a Firestorm.
Get satellite coverage over every country on one continent.
In a single game, shoot down one of each alien craft.
Build a suit of powered armor.
Cure poison on five soldiers in a single mission. Single player only.
Advance one of your soldiers to Colonel rank.
Acquire 1000 credits in one month.
Staff the Research Labs with 80 scientists.
Staff the Engineering Department with 80 engineers
In a single game, complete every Foundry project.
Build a S.H.I.V.
Build a Laboratory.
Build a Workshop.
Complete a Very Hard abduction mission in five turns or less on Classic or Impossible difficulty.
Win the game from each of the 5 starting locations.
Gain access to the lowest level in your base.
Fulfill a Council request.
Successfully assault an Overseer UFO.
Recover the Hyperwave Beacon.
Make contact with the Ethereal hive mind.
Win a mission with an all-female squad. Single player only.
Complete Friends in Low Places.
Complete Confounding Light.
Complete Gangplank.
Take your new ally into the final challenge.
Complete Confounding Light with more than 3 turns left on the timer.