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