There are 49 achievements worth a total of 1000 points
Completed mission 1 on any difficulty.
Completed mission 2 on any difficulty.
Completed mission 3 on any difficulty.
Completed mission 4 on any difficulty.
Completed mission 5 on any difficulty.
Completed mission 6 on any difficulty.
Completed mission 7 on any difficulty.
Completed mission 8 on any difficulty.
Completed the Campaign on Normal or harder.
Completed the Campaign on Heroic or harder.
Completed the Campaign on Legendary difficulty.
Completed the Campaign solo on Legendary difficulty.
Completed any Campaign mission with 3 or more Skulls on Heroic or harder.
Completed any Campaign mission cooperatively on Heroic or harder.
Found a Terminal in the Campaign.
Found all of the Terminals in the Campaign.
Found and accessed Chief's record in mission 1.
Got significant air in the Warthog at midnight in mission 2.
Carried a UNSC weapon all the way through mission 3 on Heroic or harder.
Completed mission 4 without one preventable Marine death on Heroic or harder.
Hijacked a Wraith and used it to kill at least four enemy Wraiths in mission 5 on Heroic or harder.
Tricked or forced a Hunter to fall to his demise in mission 6.
Took out both Hunters using only the Sticky Detonator in mission 7.
Killed 3 Crawlers in one hit with the Gravity Hammer in mission 8.
Ranked up your Spartan-IV to SR-5.
Ranked up your Spartan-IV to SR-20.
Won 5 War Games matchmaking matches.
Won 20 War Games matchmaking matches.
Completed a Spartan Ops Mission on any difficulty.
Completed all chapters in Spartan Ops Episode 1 on Legendary difficulty.
Completed all chapters in the first 5 episodes of Spartan Ops on any difficulty.
Completed a Spartan Ops chapter solo on Legendary.
Found one of the RvB Easter Eggs in Spartan Ops.
Saved at least one Marine in Chapter 3 of Episode 2 of Spartan Ops on Heroic or harder.
Assassinated a Knight in any Spartan Ops mission.
Completed Chapter 4, Episode 5 of Spartan Ops without losing a generator on Heroic or harder.
In Ch 1, Ep 5 of Spartan Ops survived the enemy assault during the defense on Normal or harder.
Completed a Challenge.
Completed 25 Challenges.
Changed your Spartan's armor in the Spartan Armor card.
Changed your Emblem in the Spartan ID card.
Changed your Service Tag in the Spartan ID card.
Changed your Spartan's pose in the Spartan ID card.
Created and saved a Custom Map in Forge.
Created and saved a Custom Game type in War Games.
Saved a Screenshot from the Theater.
Saved a Film Clip from the Theater.
Uploaded a File to your File Share.
Completed the Campaign cooperatively on Heroic or harder.