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.
Sabotage a dreadnought.
Evacuate a scientific facility.
Finish all multiplayer maps on Gold or all single-player missions on Insanity.
Finish the game on Insanity without changing difficulty after leaving Earth.
Overload the shields of 100 enemies.
Kill 5,000 enemies.
Upgrade any weapon to level 10.
Complete Mass Effect 3 twice, or once with a Mass Effect 2 import.
Mission accomplished.
Make the final assault.
Defeat an old adversary.
Deliver most of the Galaxy at War assets to the final conflict.
Send a warning across the galaxy.
Extract ancient technology.
Call down an orbital strike.
Establish or rekindle a romantic relationship.
Disable a group of fighter squadrons.
Discover an enemy's monstrous origin.
Win a political stand-off.
Explore a lost city.
Dispatch 10 probes to retrieve people or resources in Reaper territory.
Survive the swarm.
Defeat a harvester.
Destroy an Atlas dropped from orbit.
Stop a Cerberus kidnapping.
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.
Perform any combination of 50 biotic combos or tech bursts.
Bring a veteran officer aboard.
Escape a Reaper in the galaxy map.
Hijack an Atlas mech.
Kill 1,000 enemies.
Attain the highest level of readiness in each theater of war.
Set 100 enemies on fire with powers.
Kill 10 guardians with headshots from the front while their shields are raised.
Finish all multiplayer maps or all N7 missions in single-player.
Obtain two non-customizable suits of armor.
Visit a store in the single-player campaign.
Chase down an assassin.
Return to active duty.
Reach level 15 in multiplayer or level 50 in single-player.
Kill 250 enemies.
Evolve any of your powers to rank 6.
Complete three multiplayer matches or five N7 missions.
Lift 100 enemies off the ground with powers.
Kill 100 enemies with melee attacks.
Modify a weapon.
Complete one multiplayer match or two N7 missions.
Kill a brute while it's charging you.
Start a character in multiplayer or customize a character in single-player.
Find all required intel to help Eden Prime's colonists.
Learn more about the Prothean Empire.
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.
Win a prize at one of the arcade games.
Defeat a group of Spectre-level opponents on Normal, Hardcore, or Insanity.
Investigate a strange occurrence in the combat simulator.
Score 9999 points in the combat simulator on Normal, Hardcore, or Insanity.
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.