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.
Overload the shields of 100 enemies.
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.
Make the final assault.
Defeat an old adversary.
Hijack an Atlas mech.
Deliver most of the Galaxy at War assets to the final conflict.
Upgrade any weapon to level 10.
Attain the highest level of readiness in each theater of war.
Send a warning across the galaxy.
Kill a brute while it's charging you.
Finish all multiplayer maps or all N7 missions in single-player.
Extract ancient technology.
Call down an orbital strike.
Disable a group of fighter squadrons.
Sabotage a dreadnought.
Discover an enemy's monstrous origin.
Establish or rekindle a romantic relationship.
Perform any combination of 50 biotic combos or tech bursts.
Kill 1,000 enemies.
Evacuate a scientific facility.
Win a political stand-off.
Kill 10 guardians with headshots from the front while their shields are raised.
Explore a lost city.
Lift 100 enemies off the ground with powers.
Defeat a harvester.
Survive the swarm.
Destroy an Atlas dropped from orbit.
Dispatch 10 probes to retrieve people or resources in Reaper territory.
Stop a Cerberus kidnapping.
Kill 100 enemies with melee attacks.
Reach level 15 in multiplayer or level 50 in single-player.
Evolve any of your powers to rank 6.
Complete three multiplayer matches or five N7 missions.
Complete one multiplayer match or two N7 missions.
Start a character in multiplayer or customize a character in single-player.
Bring a veteran officer aboard.
Kill 250 enemies.
Escape a Reaper in the galaxy map.
Set 100 enemies on fire with powers.
Obtain two non-customizable suits of armor.
Visit a store in the single-player campaign.
Chase down an assassin.
Modify a weapon.
Return to active duty.
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.
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.