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 the game on Insanity without changing difficulty after leaving Earth.
Finish all multiplayer maps on Gold or all single-player missions on Insanity.
Hijack an Atlas mech.
Kill 5,000 enemies.
Overload the shields of 100 enemies.
Kill 10 guardians with headshots from the front while their shields are raised.
Reach level 20 in multiplayer or level 60 in single-player.
Kill 100 enemies with melee attacks.
Upgrade any weapon to level 10.
Attain the highest level of readiness in each theater of war.
Promote a multiplayer character to the Galaxy at War or import an ME3 character.
Mission accomplished.
Complete Mass Effect 3 twice, or once with a Mass Effect 2 import.
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.
Kill 1,000 enemies.
Obtain two non-customizable suits of armor.
Finish all multiplayer maps or all N7 missions in single-player.
Extract ancient technology.
Start a character in multiplayer or customize a character in single-player.
Call down an orbital strike.
Disable a group of fighter squadrons.
Complete three multiplayer matches or five N7 missions.
Sabotage a dreadnought.
Reach level 15 in multiplayer or level 50 in single-player.
Evacuate a scientific facility.
Discover an enemy's monstrous origin.
Establish or rekindle a romantic relationship.
Win a political stand-off.
Explore a lost city.
Lift 100 enemies off the ground with powers.
Kill a brute while it's charging you.
Defeat a harvester.
Complete one multiplayer match or two N7 missions.
Perform any combination of 50 biotic combos or tech bursts.
Survive the swarm.
Dispatch 10 probes to retrieve people or resources in Reaper territory.
Escape a Reaper in the galaxy map.
Destroy an Atlas dropped from orbit.
Kill 250 enemies.
Stop a Cerberus kidnapping.
Evolve any of your powers to rank 6.
Bring a veteran officer aboard.
Set 100 enemies on fire with powers.
Modify a weapon.
Visit a store in the single-player campaign.
Chase down an assassin.
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.
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.
Throw a party for your friends.
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.