Full list of all 46 Aliens: Fireteam Elite achievements worth 1,115 gamerscore. It takes around 100-120 hours to unlock all of the achievements in the base game.
The base game contains 42 achievements worth 1,000 Gamerscore, and there are 2 DLC packs containing 4 achievements worth 115 Gamerscore.
Eliminate 1000 Synthetics.
Kill 1000 enemies with fire.
Collected 40 weapon colors on a single character.
Finish all Campaigns on Intense Difficulty.
Collected 40 decals on a single character.
Collected 20 hats on a single character.
Heal your fireteam with an aid kit 100 times.
Finish a mission on Extreme Difficulty.
Open 50 hidden caches.
Returned 39 pieces of intel on a single character.
Finish all Campaigns on Standard Difficulty.
Complete 25 successful Challenge runs.
Finish the "Only Way to be Sure" Campaign.
Eliminate 10000 Xenomorphs.
Finish the "Gift of Fire" Campaign.
Eliminate 300 Pathogen.
Collected 20 emotes on a single character.
Level a Kit to Rank 8.
Level a weapon to four stars.
Fill every slot in a perk board.
Finish a mission on Intense Difficulty.
Finish the "Giants in the Earth" Campaign.
Collected one attachment of every type on a single character.
Collected 25 attachments on a single character.
Equip three attachments on a single weapon.
Finish the "Priority One" Campaign.
Kill 50 enemies with explosive barrels or pods.
Get grappled five times in the same mission.
Do a successful Challenge run.
Change your hat and outfit.
Equip a colorway and decal onto a gun.
Finish a mission on Insane Difficulty.
Finish all Campaigns on Extreme Difficulty.
Finish all Campaigns on Insane Difficulty.
Level five Kits to Rank 8 on a single character.
Level 30 weapons to four stars on a single character.
Eliminate 2000 elite enemies.
Kill 1000 enemies with electricity.
Use 500 consumables.
Complete 50 missions without anyone being downed.
Complete a mission on Intense Difficulty or above without anyone taking friendly fire damage.
Complete a mission without using aid kits, ammo crates, or consumables.
Finish the "Promise of a Flower" Campaign.
Return 48 pieces of intel on a single character.
Destroy 50 explosive spore pods with Weapons or Abilities.
Finish a mission on Hardcore 10 Difficulty.