Halo 3: ODST

Found 15 Audio Logs, alone or with another ODST.

Found all Audio Logs, alone or with another ODST.

In Firefight, finished a full round without killing a single enemy.

Got 10 automag headshot kills in any level.

Got 10 Rocket kills on Kizingo Boulevard.

Completed the Campaign on Heroic difficulty.

Completed Legendary and unlocked the Dare character in Firefight.

Completed the Campaign on Normal difficulty.

Completed Coastal Highway and unlocked the Last Exit Firefight mission.

Killed 5 enemies while using VISR mode.

Completed Data Hive and unlocked the Chasm Ten Firefight mission.

Got 15 headshot kills on NMPD HQ.

Got 5 sticky grenade kills in any level.

Scored over 200,000 points in Firefight on Alpha Site.

Scored over 200,000 points in Firefight on Chasm Ten.

Scored over 200,000 points in Firefight on Crater.

Scored over 200,000 points in Firefight on Last Exit.

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 Windward.

Killed no Engineers in the city at night during entire campaign, alone or with another ODST.

Found the 3rd clue unraveling the mystery, alone or with another ODST.

Finished any level with at least one Skull activated.

Found the first Medical Kiosk and healed yourself.

Killed 10 enemies with the Flamethrower on Data Hive.

Found the first clue unraveling the mystery.

Completed Kikowani Station on Normal, Heroic, or Legendary.

Completed Kizingo Blvd. and unlocked the Mickey character in Firefight.

Got 10 Spartan Laser kills on ONI Alpha Site.

Found the first Audio Log.

Plasma Pistol Overcharged and quickly killed 10 Brutes.

Killed 10 Engineers in the city at night, alone or with another ODST.

Completed NMPD HQ and unlocked the Romeo character in Firefight.

Completed ONI Alpha Site and unlocked the Alpha Site Firefight mission.

Got 10 Needler supercombine kills on any covenant.

Stunned a vehicle with an overcharged plasma pistol and quickly killed the driver.

Found the final clue unraveling the mystery, alone or with another ODST.

Completed Tayari Plaza and unlocked the Buck character in Firefight.

Accessed and downloaded the city map to your VISR.

Traded weapons with a fellow character.

Found 3 Audio Logs, alone or with another ODST.

Completed Uplift Reserve and unlocked the Dutch character in Firefight.

Finished any level solo on Legendary, on LIVE, with no shots fired or grenades thrown.

Completed Highway on 4-player Legendary LIVE co-op, with Iron, and no 'Hog or Scorpion.

In Firefight, on any mission, passed the 4th Set on 4-player Heroic LIVE co-op.

Killed all Wraiths in Uplift Reserve.