CheatCodes.com has the complete list of all Halo: Reach Achievements and Gamerscores for X360, including all secret Achievements. All official X360 achievements for Halo: Reach as of Wednesday September 2, 2015 are shown below, or you can print out our Printable Achievements Checklist that shows all Halo: Reach Achievements and Gamerscores in a simple quick-reference format.
Complete each Campaign Mission on Legendary - alone.
Complete the Campaign on Legendary difficulty.
Purchase any item from the Armory.
Use a Health Pack to recover life after taking body damage.
Kill 10 Enemies in a Firefight or Campaign session with the M6G pistol.
Clear the 2nd mission without setting foot in a drivable vehicle.
Kill 7 Moa during the 2nd mission of the Campaign.
Kill 10 enemies in a Firefight or Campaign session with the DMR.
Complete the 2nd mission on Normal or harder.
Kill 2 vehicles at once with the Target Locator during the 3rd mission.
Trade weapons with an AI ally in Campaign.
Kill 10 enemies in Firefight or Campaign with a supercombine explosion.
Complete the 3rd mission on Normal or harder.
Perform an Assassination on an enemy.
Complete the 4th mission on Normal or harder.
Kill the Elite Zealot before he can escape during the 5th mission.
Complete the 5th mission on Normal or harder.
Destroy the Corvette's engines & escort in under 3 minutes in the 6th mission on Heroic or harder.
Complete the 6th mission on Normal or harder.
Earn a Triple Kill while Jetpacking in Campaign, Firefight or Matchmaking.
Complete the 7th mission on Normal or harder.
Reach the rank of Corporal in the UNSC.
Kill 3 of the anti-aircraft batteries during the 8th mission.
Complete the 8th mission on Normal or harder.
Finish the 9th mission on Legendary with the Scorpion intact.
Hijack a Banshee during the Reach Campaign.
Complete the 9th mission on Normal or harder.
Perform an Assassination against an Elite to survive a fall that would've been fatal.
Complete the 10th mission on Normal or harder.
Complete the Campaign on Heroic difficulty.
Complete the Campaign on Normal difficulty.
Earn a Killing Spree in multiplayer Matchmaking.
Let a teammate spawn on you 5 times in an Invasion Matchmaking game.
Win a game of Invasion in the 1st phase.
Earn a First Strike Medal in a Matchmaking game.
As an Elite, kill 5 Spartan players in Matchmaking.
Score 15,000 points in Score Attack Firefight Matchmaking.
Earn a Killionaire medal in Firefight.
Complete a Firefight set on Legendary without dying.
Score 50,000 points in Firefight on any map.
Score 200,000 points in Firefight on any map.
Score 1,000,000 points in Firefight on any map.
Using the File Browser upload a file to your File Share.
Complete a Weekly Challenge.
Recommend a file to someone.
Complete all of the Daily Challenges in a given day.
Reach the rank of Captain in the UNSC.
Advance any Commendation to its Silver state.
Purchase an item from the Armory that requires the rank of Lt. Colonel.