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.
Finish all multiplayer maps on Gold or all single-player missions on Insanity.
Finish the game on Insanity without changing difficulty after leaving Earth.
Hijack an Atlas mech.
Promote a multiplayer character to the Galaxy at War or import an ME3 character.
Overload the shields of 100 enemies.
Kill 100 enemies with melee attacks.
Kill 5,000 enemies.
Kill 10 guardians with headshots from the front while their shields are raised.
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.
Disable a group of fighter squadrons.
Establish or rekindle a romantic relationship.
Obtain two non-customizable suits of armor.
Attain the highest level of readiness in each theater of war.
Reach level 20 in multiplayer or level 60 in single-player.
Finish all multiplayer maps or all N7 missions in single-player.
Upgrade any weapon to level 10.
Sabotage a dreadnought.
Reach level 15 in multiplayer or level 50 in single-player.
Complete three multiplayer matches or five N7 missions.
Kill 1,000 enemies.
Evacuate a scientific facility.
Discover an enemy's monstrous origin.
Win a political stand-off.
Explore a lost city.
Kill a brute while it's charging you.
Defeat a harvester.
Start a character in multiplayer or customize a character in single-player.
Complete one multiplayer match or two N7 missions.
Survive the swarm.
Destroy an Atlas dropped from orbit.
Dispatch 10 probes to retrieve people or resources in Reaper territory.
Escape a Reaper in the galaxy map.
Stop a Cerberus kidnapping.
Evolve any of your powers to rank 6.
Bring a veteran officer aboard.
Kill 250 enemies.
Visit a store in the single-player campaign.
Chase down an assassin.
Set 100 enemies on fire with powers.
Lift 100 enemies off the ground with powers.
Perform any combination of 50 biotic combos or tech bursts.
Modify a weapon.
Return to active duty.
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.
Defeat a group of Spectre-level opponents on Normal, Hardcore, or Insanity.
Investigate a strange occurrence in the combat simulator.
Throw a party for your friends.
Win a prize at one of the arcade games.
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.