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