The Halo Reach: Campaign Add-on for Halo: The Master Chief Collection has 91 achievements worth 920 gamerscore.
Halo: Reach: Complete a Firefight set on Normal or harder.
Halo: Reach: Complete Winter Contingency.
Halo: Reach: Observe a grizzly scene on New Alexandria.
Halo: Reach: Complete ONI: Sword Base.
Halo: Reach: Complete Nightfall.
Halo: Reach: Complete Tip of the Spear.
Halo: Reach: Complete Long Night of Solace.
Halo: Reach: Complete Exodus.
Halo: Reach: Complete New Alexandria.
Halo: Reach: Complete The Package.
Halo: Reach: Complete The Pillar of Autumn.
Halo: Reach: Complete every level of the game on Easy difficulty.
Halo: Reach: Complete every level of the game on Normal difficulty.
Halo: Reach: Complete every level of the game on Heroic difficulty.
Halo: Reach: Complete every level of the game on Legendary difficulty.
Halo: Reach: Complete every level of the game on Legendary difficulty, by yourself.
Halo: Reach: Beat the par time on Winter Contingency.
Halo: Reach: Beat the par time on ONI: Sword Base.
Halo: Reach: Beat the par time on Nightfall.
Halo: Reach: Beat the par time on Tip of the Spear.
Halo: Reach: Beat the par time on Long Night of Solace.
Halo: Reach: Beat the par time on Exodus.
Halo: Reach: Beat the par time on New Alexandria.
Halo: Reach: Beat the par time on The Package.
Halo: Reach: Beat the par time on The Pillar of Autumn.
Halo: Reach: Beat par time on all Halo: Reach levels.
Halo: Reach: Beat the par score on Winter Contingency.
Halo: Reach: Beat the par score on ONI: Sword Base.
Halo: Reach: Beat the par score on Nightfall.
Halo: Reach: Beat the par score on Tip of the Spear.
Halo: Reach: Beat the par score on Long Night of Solace.
Halo: Reach: Beat the par score on Exodus.
Halo: Reach: Beat the par score on New Alexandria.
Halo: Reach: Beat the par score on The Package.
Halo: Reach: Beat the par score on The Pillar of Autumn.
Halo: Reach: Beat the par score on every Halo: Reach level.
Halo: Reach: Kill 100 Skirmishers.
Halo: Reach: Kill 1000 Skirmishers.
Halo: Reach: Kill 7 Moa during Winter Contingency.
Halo: Reach: Clear Winter Contingency without setting foot in a drivable vehicle.
Halo: Reach: Destroy the Corvette's engines & escort in under 3 minutes during Long Night of Solace
Halo: Reach: Kill 2 vehicles at once with the Target Locator during ONI: Sword Base.
Halo: Reach: Kill the Elite Zealot before he can escape during Tip of the Spear.
Halo: Reach: Kill 3 of the anti-aircraft batteries during New Alexandria.
Halo: Reach: Finish The Package on Legendary with the Scorpion intact.
Halo: Reach: Hijack a Banshee during the Reach Campaign.
Halo: Reach: Flip the switches to become a Reach Racer!
Halo: Reach: Party with the DJ Brute.
Halo: Reach: Listen to a hidden music cue.
Halo: Reach: Fly both the Pelican and Phantom on New Alexandria.
Halo: Reach: Find me in the club.
Halo: Reach: Now that's a value meal.
Halo: Reach: Encounter the hidden marines on Exodus.
Halo: Reach: Find the hidden Banshees on The Package.
Halo: Reach: Find your way into Halsey's Lab on The Package.
Halo: Reach: Find Data Pad on 1 Winter Contingency
Halo: Reach: Find Data Pad 2 on ONI: Sword Base
Halo: Reach: Find Data Pad 3 on Nightfall
Halo: Reach: Find Data Pad 4 on Tip Of The Spear
Halo: Reach: Find Data Pad 5 on Long Night Of Solace
Halo: Reach: Find Data Pad 6 on Exodus
Halo: Reach: Find Data Pad 7 on New Alexandria
Halo: Reach: Find Data Pad 8 on The Package
Halo: Reach: Find Data Pad 9 on The Pillar Of Autumn
Halo: Reach: Find Data Pad 10 on Winter Contingency on Legendary difficulty
Halo: Reach: Find Data Pad 11 on ONI: Sword Base on Legendary difficulty
Halo: Reach: Find Data Pad 12 on Nightfall on Legendary difficulty
Halo: Reach: Find Data Pad 13 on Tip Of The Spear on Legendary difficulty
Halo: Reach: Find Data Pad 14 on Long Night Of Solace on Legendary difficulty
Halo: Reach: Find Data Pad 15 on Exodus on Legendary difficulty
Halo: Reach: Find Data Pad 16 on New Alexandria on Legendary difficulty
Halo: Reach: Find Data Pad 17 on The Package on Legendary difficulty
Halo: Reach: Find Data Pad 18 on The Pillar Of Autumn on Legendary difficulty
Halo: Reach: Find Data Pad 19 on Lone Wolf on Legendary difficulty
Halo: Reach: Find all Data Pads.
Halo: Reach: Complete the Halo: Reach LASO Campaign playlist.
Halo: Reach: Complete a Halo: Reach playlist.
Halo: Reach: Complete three Halo: Reach playlists.
Halo: Reach: Play a game of Halo: Reach on the 14th of any month.
Halo: Reach: Complete all Halo: Reach Legendary campaign missions in under 3 hours.
Halo: Reach: Pad on the run.
Halo: Reach: Achieve a score of 30,000 points on Lone Wolf.
Halo: Reach: Achieve a score of 150,000 points on Lone Wolf.
Halo: Reach: Find and eliminate one of the hidden Ranger Commander Elites.
Halo: Reach: Use a Pelican turret.
Halo: Reach: Splatter an enemy using the forklift.
Halo: Reach: Complete a Legendary campaign mission with 3 or more skulls enabled (Scoring Only).
Halo: Reach: Complete Exodus without using any armour abilities.
Halo: Reach: See, he IS in the game!
Halo: Reach: Observe the logo of a buttoned-up mining company.
Halo: Reach: Hear a familiar voice on New Alexandria.