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