Kill 100 enemies with headshots.
Complete Halo.
Complete Pillar of Autumn.
Collect a Skull.
Complete Boarding Action.
Complete Keyes.
Complete The Maw.
Complete The Most Dangerous Game.
Complete Heavy Burden.
Complete the Campaign on Easy Difficulty.
Complete the Campaign on Normal Difficulty.
Complete the Campaign on Heroic Difficulty.
Complete the Campaign on Legendary Difficulty.
Activate all 13 Terminals.
Find all skulls and terminals in Pillar of Autumn.
Find all skulls and terminals in Halo.
Find all skulls and terminals in Truth and Reconciliation.
Find all skulls and terminals in Silent Cartographer.
Find all skulls and terminals in Assault on the Control Room.
Find all skulls and terminals in 343 Guilty Spark.
Find all skulls and terminals in The Library.
Find all skulls and terminals in Two Betrayals.
Find all skulls and terminals in Keyes.
Find all skulls and terminals in The Maw.
Find all skulls and terminals in Boarding Action.
Find all skulls and terminals in The Most Dangerous Game.
Find all skulls and terminals in Heavy Burden.
Collect 22 Skulls.
Collect all 39 Skulls.
Find all skulls and terminals in the game.
Complete a Remixed Mission.
Complete a Remixed Mission without dying.
Complete an entire Remixed Campaign without dying.
Complete Truth and Reconciliation.
Destroy 100 Grunt backpacks.
Break off 25 Hunter backplates.
Hijack 10 Vehicles.
Dismember 100 Flood parts.
Break off 50 Vehicle parts.
With the Floor Is Lava Skull activated beat a mission without jumping or dying.
With the Temperamental Skull activated beat Halo without upsetting anyone.
Complete Two Betrayals with the Speed Limit, Endurance Spec, Hip Fire, and Armistice Skulls enabled.
Equip Famine, Recession, and Johnny Ammo Tree Skulls and beat a mission without running out of ammo.
Complete Silent Cartographer.
Complete the Campaign with LASO enabled
Eliminate Captain Keyes and trap his six avenging Marines in the Autumn's observation pen.
Complete The Silent Cartographer without shooting, using grenades, melee, dying, or restarting.
On Assault on the Control Room get to the Banshee before the Elite
On 343 Guilty Spark complete the first floor without taking a hit
On The Maw complete the warthog run without being forcibly ejected from your vehicle.
On The Most Dangerous Game don't kill any rampaging Brutes
Listen to the Thirsty Grunt talk about his eating habits
Complete any level on Heroic difficulty or higher without taking health damage
Complete Every Achievement.
Complete Assault on the Control Room.
Complete 343 Guilty Spark.
Complete The Library.
Complete Two Betrayals.
