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