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.
Overload the shields of 100 enemies.
Kill 5,000 enemies.
Finish the game on Insanity without changing difficulty after leaving Earth.
Upgrade any weapon to level 10.
Lift 100 enemies off the ground with powers.
Promote a multiplayer character to the Galaxy at War or import an ME3 character.
Complete Mass Effect 3 twice, or once with a Mass Effect 2 import.
Mission accomplished.
Make the final assault.
Reach level 20 in multiplayer or level 60 in single-player.
Attain the highest level of readiness in each theater of war.
Defeat an old adversary.
Deliver most of the Galaxy at War assets to the final conflict.
Send a warning across the galaxy.
Finish all multiplayer maps or all N7 missions in single-player.
Extract ancient technology.
Perform any combination of 50 biotic combos or tech bursts.
Kill 100 enemies with melee attacks.
Call down an orbital strike.
Disable a group of fighter squadrons.
Sabotage a dreadnought.
Discover an enemy's monstrous origin.
Evacuate a scientific facility.
Establish or rekindle a romantic relationship.
Win a political stand-off.
Explore a lost city.
Kill 1,000 enemies.
Kill 10 guardians with headshots from the front while their shields are raised.
Defeat a harvester.
Survive the swarm.
Destroy an Atlas dropped from orbit.
Obtain two non-customizable suits of armor.
Dispatch 10 probes to retrieve people or resources in Reaper territory.
Stop a Cerberus kidnapping.
Bring a veteran officer aboard.
Kill a brute while it's charging you.
Set 100 enemies on fire with powers.
Reach level 15 in multiplayer or level 50 in single-player.
Complete three multiplayer matches or five N7 missions.
Escape a Reaper in the galaxy map.
Kill 250 enemies.
Complete one multiplayer match or two N7 missions.
Modify a weapon.
Visit a store in the single-player campaign.
Chase down an assassin.
Return to active duty.
Evolve any of your powers to rank 6.
Start a character in multiplayer or customize a character in single-player.
Hijack an Atlas mech.
Finish all multiplayer maps on Gold or all single-player missions on Insanity.
Find all required intel to help Eden Prime's colonists.
Learn more about the Prothean Empire.
Investigate a sinister conspiracy.
Uncover an ancient secret.
Use clues to pinpoint the exact location of an objective.
Rescue a civilian from Reaper forces.
Free Omega from Cerberus Occupation.
Find the Talon leader.
Complete all the Command Center side-missions on Omega.
Discover a plot against you.
Go undercover to follow a lead.
Infiltrate an enemy stronghold with your crew.
Stop an out-of-control scheme before it's too late.
Throw a party for your friends.
Win a prize at one of the arcade games.
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.