A Monument To All Your Sins - Completed every mission in Halo
A New Challenger - Completed all of the Daily Challenges in a given day.
A Spoonful Of Blamite - Killed 10 enemies in Firefight or Campaign with a supercombine explosion.
A Storage Solution - Used the File Browser to upload a file to your File Share.
An Elegant Weapon - Killed 10 enemies in a Firefight or Campaign session with the DMR.
An Honor Serving - Reached the rank of Captain in the UNSC.
Banshees, Fast And Low - Hijacked a Banshee during the Reach Campaign.
Be My Wingman Anytime - Let a teammate spawn on you 5 times in an Invasion Matchmaking game.
Blaze Of Glory - Scored 200,000 points in a Firefight game.
Cool, File Bro - Recommended a file to someone.
Crowd Control - Earned a Killionaire medal in Firefight.
Doctor, Doctor - Used a Health Pack to replenish life after taking body damage.
Dust And Echoes - Completed the 8th mission on Normal or harder.
Firestarter - Scored 50,000 points in a Firefight game.
Folks Need Heroes... - Completed the Campaign on Heroic difficulty.
Game, Set, Match - Completed a Firefight set on Legendary without dying.
Gods Must Be Strong - Completed the Campaign on Legendary difficulty.
Heat In The Pipe - Scored 1,000,000 points in a Firefight game.
I Didn't Train To Be A Pilot - Killed 3 of the anti-aircraft batteries during the 8th mission.
I Need A Weapon - Completed the 4th mission on Normal or harder.
I See You Favour A .45 - Killed 10 enemies in a Firefight or Campaign session with the M6G pistol.
If They Came To Hear Me Beg - Performed an Assassination against an Elite to survive a fall that would've been fatal.
Into The Howling Dark - Completed the 7th mission on Normal or harder.
KEEP IT CLEAN - Killed 7 Moa during the 2nd mission of the Campaign.
Knife To A Gun Fight - As an Elite, killed 5 Spartan players in Matchmaking.
Lemme Upgrade Ya - Advanced a Commendation to a Silver state.
Lucky Me - Earned a Triple Kill while Jetpacking in Campaign, Firefight or Matchmaking.
Make It Drizzle - Purchased an item from the Armory.
Make It Rain - Purchased an item from the Armory that required the rank of Lt. Colonel.
One Down, 51 To Go - Completed a Weekly Challenge.
Protocol Dictates Action - Completed the 3rd mission on Normal or harder.
Score Attack - Scored 15,000 points in Score Attack Firefight Matchmaking.
Send Me Out... With A Bang - Completed the 10th mission on Normal or harder.
Skunked - Won a game of Invasion in the 1st phase.
Swap Meet - Traded weapons with an AI ally in Campaign.
Tank Beats Everything - Finished the 9th mission on Legendary with the Scorpion intact.
That's A Knife - Performed an Assassination on an enemy.
The Soldier We Need You To Be - Completed the Campaign on Normal difficulty.
The Start Of Something - Reached the rank of Corporal in the UNSC.
They've Always Been Faster - Cleared the 2nd mission without setting foot in a drivable vehicle.
This Is Not Your Grave - Completed the 9th mission on Normal or harder.
To War - Completed the 5th mission on Normal or harder.
Two Corpses In One Grave - Killed 2 vehicles at once with the Target Locator in the 3rd mission.
Wake Up Buttercup - Destroyed the Corvette's engines & escort in under 3 minutes in the 6th mission on Heroic or harder.
We're Just Getting Started - Completed the 2nd mission on Normal or harder.
What's A Killing Spree? - Earned a Killing Spree in multiplayer Matchmaking.
Yes, Sensei - Earned a First Strike Medal in a Matchmaking game.
You Flew Pretty Good - Completed the 6th mission on Normal or harder.
Your Heresy Will Stay Your Feet - Killed the Elite Zealot before he escaped during the 5th mission.
[more cheats for Halo: Reach here]