Full list of all 68 Mass Effect 3 achievements worth 1,550 gamerscore. It takes around 50-60 hours to unlock all of the achievements in the base game.
The base game contains 50 achievements worth 1,000 Gamerscore, and there are 4 DLC packs containing 18 achievements worth 550 Gamerscore.
Kill 5,000 enemies.
Overload the shields of 100 enemies.
Upgrade any weapon to level 10.
Promote a multiplayer character to the Galaxy at War or import an ME3 character.
Reach level 20 in multiplayer or level 60 in single-player.
Mission accomplished.
Complete Mass Effect 3 twice, or once with a Mass Effect 2 import.
Finish the game on Insanity without changing difficulty after leaving Earth.
Finish all multiplayer maps on Gold or all single-player missions on Insanity.
Make the final assault.
Defeat an old adversary.
Deliver most of the Galaxy at War assets to the final conflict.
Attain the highest level of readiness in each theater of war.
Send a warning across the galaxy.
Finish all multiplayer maps or all N7 missions in single-player.
Extract ancient technology.
Call down an orbital strike.
Kill 1,000 enemies.
Complete three multiplayer matches or five N7 missions.
Disable a group of fighter squadrons.
Sabotage a dreadnought.
Lift 100 enemies off the ground with powers.
Establish or rekindle a romantic relationship.
Discover an enemy's monstrous origin.
Perform any combination of 50 biotic combos or tech bursts.
Evacuate a scientific facility.
Reach level 15 in multiplayer or level 50 in single-player.
Win a political stand-off.
Hijack an Atlas mech.
Explore a lost city.
Defeat a harvester.
Complete one multiplayer match or two N7 missions.
Survive the swarm.
Kill 100 enemies with melee attacks.
Destroy an Atlas dropped from orbit.
Obtain two non-customizable suits of armor.
Stop a Cerberus kidnapping.
Kill 10 guardians with headshots from the front while their shields are raised.
Bring a veteran officer aboard.
Kill 250 enemies.
Kill a brute while it's charging you.
Set 100 enemies on fire with powers.
Dispatch 10 probes to retrieve people or resources in Reaper territory.
Escape a Reaper in the galaxy map.
Modify a weapon.
Visit a store in the single-player campaign.
Chase down an assassin.
Return to active duty.
Evolve any of your powers to rank 6.
Start a character in multiplayer or customize a character in single-player.
Learn more about the Prothean Empire.
Find all required intel to help Eden Prime's colonists.
Uncover an ancient secret.
Rescue a civilian from Reaper forces.
Investigate a sinister conspiracy.
Use clues to pinpoint the exact location of an objective.
Free Omega from Cerberus Occupation.
Complete all the Command Center side-missions on Omega.
Find the Talon leader.
Throw a party for your friends.
Investigate a strange occurrence in the combat simulator.
Defeat a group of Spectre-level opponents on Normal, Hardcore, or Insanity.
Score 9999 points in the combat simulator on Normal, Hardcore, or Insanity.
Win a prize at one of the arcade games.
Stop an out-of-control scheme before it's too late.
Infiltrate an enemy stronghold with your crew.
Go undercover to follow a lead.
Discover a plot against you.