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