Found all Audio Logs, alone or with another ODST.
Killed 10 Engineers in the city at night, alone or with another ODST.
Found 15 Audio Logs, alone or with another ODST.
In Firefight, finished a full round without killing a single enemy.
Got 10 Needler supercombine kills on any covenant.
Plasma Pistol Overcharged and quickly killed 10 Brutes.
Finished any level solo on Legendary, on LIVE, with no shots fired or grenades thrown.
Finished any level with at least one Skull activated.
Killed all Wraiths in Uplift Reserve.
Stunned a vehicle with an overcharged plasma pistol and quickly killed the driver.
Killed 10 enemies with the Flamethrower on Data Hive.
Got 5 sticky grenade kills in any level.
Got 10 Rocket kills on Kizingo Boulevard.
Got 10 Spartan Laser kills on ONI Alpha Site.
Completed the Campaign on Heroic difficulty.
Completed Legendary and unlocked the Dare character in Firefight.
Completed Coastal Highway and unlocked the Last Exit Firefight mission.
Completed the Campaign on Normal difficulty.
Completed Data Hive and unlocked the Chasm Ten Firefight mission.
Killed no Engineers in the city at night during entire campaign, alone or with another ODST.
Completed Kikowani Station on Normal, Heroic, or Legendary.
Found the final clue unraveling the mystery, alone or with another ODST.
Completed NMPD HQ and unlocked the Romeo character in Firefight.
Traded weapons with a fellow character.
Got 15 headshot kills on NMPD HQ.
Found 3 Audio Logs, alone or with another ODST.
Completed ONI Alpha Site and unlocked the Alpha Site Firefight mission.
Completed Kizingo Blvd. and unlocked the Mickey character in Firefight.
Found the 3rd clue unraveling the mystery, alone or with another ODST.
Got 10 automag headshot kills in any level.
Found the first Audio Log.
Completed Uplift Reserve and unlocked the Dutch character in Firefight.
Completed Tayari Plaza and unlocked the Buck character in Firefight.
Killed 5 enemies while using VISR mode.
Found the first clue unraveling the mystery.
Accessed and downloaded the city map to your VISR.
Found the first Medical Kiosk and healed yourself.
Scored over 200,000 points in Firefight on Lost Platoon.
Scored over 200,000 points in Firefight on Rally Point.
Scored over 200,000 points in Firefight on Security Zone.
Scored over 200,000 points in Firefight on Alpha Site.
Scored over 200,000 points in Firefight on Windward.
Scored over 200,000 points in Firefight on Chasm Ten.
Scored over 200,000 points in Firefight on Last Exit.
In Firefight, on any mission, passed the 4th Set on 4-player Heroic LIVE co-op.
Completed Highway on 4-player Legendary LIVE co-op, with Iron, and no 'Hog or Scorpion.
Scored over 200,000 points in Firefight on Crater.
