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.
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.
Overload the shields of 100 enemies.
Hijack an Atlas mech.
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.
Reach level 20 in multiplayer or level 60 in single-player.
Kill 100 enemies with melee attacks.
Complete Mass Effect 3 twice, or once with a Mass Effect 2 import.
Mission accomplished.
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.
Finish all multiplayer maps or all N7 missions in single-player.
Extract ancient technology.
Call down an orbital strike.
Disable a group of fighter squadrons.
Sabotage a dreadnought.
Perform any combination of 50 biotic combos or tech bursts.
Complete three multiplayer matches or five N7 missions.
Kill 1,000 enemies.
Evacuate a scientific facility.
Reach level 15 in multiplayer or level 50 in single-player.
Establish or rekindle a romantic relationship.
Lift 100 enemies off the ground with powers.
Discover an enemy's monstrous origin.
Win a political stand-off.
Survive the swarm.
Explore a lost city.
Defeat a harvester.
Complete one multiplayer match or two N7 missions.
Destroy an Atlas dropped from orbit.
Kill 10 guardians with headshots from the front while their shields are raised.
Obtain two non-customizable suits of armor.
Dispatch 10 probes to retrieve people or resources in Reaper territory.
Kill 250 enemies.
Escape a Reaper in the galaxy map.
Stop a Cerberus kidnapping.
Bring a veteran officer aboard.
Set 100 enemies on fire with powers.
Kill a brute while it's charging you.
Visit a store in the single-player campaign.
Chase down an assassin.
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.
Investigate a sinister conspiracy.
Uncover an ancient secret.
Use clues to pinpoint the exact location of an objective.
Rescue a civilian from Reaper forces.
Complete all the Command Center side-missions on Omega.
Free Omega from Cerberus Occupation.
Find the Talon leader.
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.
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.