Complete the level “The Library” on Heroic difficulty or higher without dying.

Unlocked: 1 Aug 2012 07:43 am

Complete the level “Halo” on any difficulty.

Unlocked: 6 Jan 2012 07:58 pm

Complete the level “Pillar of Autumn” on any difficulty.

Unlocked: 6 Jan 2012 05:51 pm

Complete any level on Normal difficulty cooperatively.

Unlocked: 6 Jan 2012 05:51 pm

Complete any level on Heroic difficulty cooperatively.

Unlocked: 6 Jan 2012 05:51 pm

Complete any level on Legendary difficulty cooperatively.

Unlocked: 6 Jan 2012 05:51 pm

Complete the level “Pillar of Autumn” on Legendary without picking up an Overshield.

Unlocked: 6 Jan 2012 05:51 pm

Complete the level “Pillar of Autumn” on Legendary without picking up a health kit.

Unlocked: 6 Jan 2012 05:51 pm

Read a terminal.

Unlocked: 6 Jan 2012 05:29 pm

Find your first campaign skull.

Unlocked: 6 Jan 2012 05:21 pm

Complete the level “The Silent Cartographer” on any difficulty.

Unlocked: Offline

Complete the level “Assault on the Control Room” on any difficulty.

Unlocked: Offline

Complete the level “Truth and Reconciliation” on any difficulty.

Unlocked: Offline

Complete the level “343 Guilty Spark” on any difficulty.

Unlocked: Offline

Complete the level “The Library” on any difficulty.

Unlocked: Offline

Complete the level “Two Betrayals” on any difficulty.

Unlocked: Offline

Complete the level “Keyes” on any difficulty.

Unlocked: Offline

Complete the level “The Maw” on any difficulty.

Unlocked: Offline

Complete any level with at least three skulls active on Heroic difficulty or higher.

Unlocked: Offline

Read half the terminals hidden throughout the campaign.

Unlocked: Offline

Read all of the terminals hidden throughout the campaign.

Unlocked: Offline

Locate half of the skulls hidden throughout the campaign.

Unlocked: Offline

Locate all the skulls hidden throughout the campaign.

Unlocked: Offline

Complete every level of the game on Normal difficulty.

Unlocked: Offline

Complete every level of the game on Heroic difficulty.

Unlocked: Offline

Complete every level of the game on Legendary difficulty.

Unlocked: Offline

Complete any level on Heroic difficulty or higher without taking health damage.

Unlocked: Offline

Destroy three of the four Banshees on “Halo” on any difficulty during a single play-through.

Unlocked: Offline

Complete the level “Halo” on any difficulty without entering a vehicle.

Unlocked: Offline

Complete the level “Truth and Reconciliation” with at least four rounds left in your Sniper Rifle.

Unlocked: Offline

Pilot a Banshee on the level “Assault on the Control Room.”

Unlocked: Offline

Kill 50 Flood Combat Forms on the level “343 Guilty Spark” on Heroic difficulty or higher.

Unlocked: Offline

Complete the level “The Library” on Legendary difficulty in 30 minutes or less.

Unlocked: Offline

Complete the level “Two Betrayals” on Heroic difficulty or higher without killing any Grunts.

Unlocked: Offline

Complete the level “Two Betrayals” on Legendary difficulty without picking up a new weapon.

Unlocked: Offline

Kill 100 Flood Infection Forms on the level “Keyes” on Heroic difficulty or above.

Unlocked: Offline

Kill all the enemies in the first encounter of “Truth and Reconciliation” without being detected.

Unlocked: Offline

Storm the beach of “The Silent Cartographer” with no marine casualties on Heroic or Legendary.

Unlocked: Offline

Escape the map room in “The Silent Cartographer” without firing a shot on Heroic or Legendary.

Unlocked: Offline

Destroy four Wraith tanks in “Assault on the Control Room” with the Scorpion tank, in a single play.

Unlocked: Offline

Escape the Forerunner facility on the level “343 Guilty Spark” in 21 minutes or less.

Unlocked: Offline

Kill every Elite on the level “Keyes” on Heroic difficulty or above.

Unlocked: Offline

Complete the Warthog ride on the level “The Maw” without being forcibly ejected from your vehicle.

Unlocked: Offline

Escape “The Maw” on Legendary with at least a minute left on the count down.

Unlocked: Offline