Full list of all 127 Mass Effect Legendary Edition achievements. It takes around 120-150 hours to unlock all of the achievements on Windows.
ME3: Sabotage a dreadnought.
Establish or rekindle a romantic relationship in all three games in Mass Effect Legendary Edition
ME3: Discover an enemy's monstrous origin.
ME3: Evacuate a scientific facility.
ME3: Win a political stand-off.
ME3: Dispatch 10 probes to retrieve people or resources in Reaper territory.
ME3: Escape a Reaper in the galaxy map.
ME3: Explore a lost city.
ME3: Survive the swarm.
ME3: Set 100 enemies on fire with powers.
ME3: Destroy an Atlas dropped from orbit.
ME3: Free Omega from Cerberus Occupation.
ME3: Uncover an ancient secret.
ME3: Defeat a harvester.
ME3: Stop a Cerberus kidnapping.
ME3: Lift 100 enemies off the ground with powers.
ME3: Upgrade any weapon to level 10.
ME3: Obtain two non-customizable suits of armor.
ME3: Bring a veteran officer aboard.
ME3: Visit a store in the single-player campaign.
ME3: Chase down an assassin.
ME3: Modify a weapon.
ME3: Return to active duty.
ME3: Evolve any of your powers to rank 6.
ME2: Keep your team alive through the suicide mission
ME2: Save humanity throughout the galaxy from certain annihilation
ME2: Survive suicide mission
ME2: Use the Omega 4 Relay
Establish or rekindle a romantic relationship in two games in Mass Effect Legendary Edition
ME2: Hack a geth collective
ME2: Obtain geth technology
ME2: Perform 30 headshot kills with any weapon on humanoid targets
ME2: Confront the Shadow Broker
ME2: Help the Justicar resolve her mission
ME2: Successfully recruit the Justicar
Kill 1,000 enemies in Mass Effect 1, 2 or 3
ME2: Gain the loyalty of the quarian
ME2: Gain the loyalty of the Assassin
ME2: Successfully recruit the quarian
ME2: Fully upgrade a weapon
ME2: Gain the loyalty of the Cerberus Officer
ME2: Successfully recruit the Assassin
ME2: Complete the investigation of a derelict alien vessel
ME2: Gain the loyalty of Archangel
ME2: Gain the loyalty of the krogan
ME2: Thresher Maw defeated
ME2: Gain the loyalty of the Professor
ME2: Gain the loyalty of the biotic Convict
ME2: Gain the loyalty of the Cerberus Operative
ME2: Evolve any power
ME2: Defend a human colony from attack
ME2: Successfully recruit the krogan
ME2: Successfully recruit the biotic Convict
ME2: Disrupt the shields of 25 enemies
ME2: Successfully recruit Archangel
ME2: Gain the loyalty of the mercenary
ME2: Visit 100% of the planets in an unexplored cluster
ME2: Successfully shut down the rogue VI in Project Overlord
ME2: Complete 5 missions discovered by scanning unexplored worlds
ME2: Complete a mission discovered by scanning an unexplored world
ME2: Gain the loyalty of the thief
ME2: Complete any research project in the Normandy's laboratory
ME2: Successfully recruit the Professor
ME2: Make 20 enemies scream as they fall or are set on fire
ME2: Unlock 15 new Mass Effect 2 codex entries
ME2: Return to active duty
ME2: Save your crew from an overwhelming attack
ME1: Complete the game on any difficulty
ME1: Complete Ilos
Establish a romantic relationship in Mass Effect 1, 2 or 3
ME1: Complete Noveria
ME1: Find all primary Alien: Council Races, Extinct Races and Non-Council Races codex entries
ME1: Complete the majority of the game
ME1: Complete Virmire
ME1: Use Charm or Intimidate to resolve an impossible situation in the game.
ME1: Complete Feros
ME1: Accumulate 75% of total possible Paragon or Renegade points
Kill 250 enemies in Mass Effect 1, 2 or 3
ME1: Use Shield Overload 25 times
ME1: Complete the Bring Down the Sky mission.
ME1: Land on 8 uncharted worlds
ME1: Land on 4 uncharted worlds
ME1: Complete 5 missions with the asari squad member
ME1: Complete 5 missions with the Alliance soldier squad member
ME1: Complete 5 missions with the krogan squad member
ME1: Complete 5 missions with the turian squad member
ME1: Locate Dr. T'soni in the Artemis Tau cluster
ME1: Land on an uncharted world
ME1: Complete 5 missions with the quarian squad member
ME1: Become a Spectre
ME1: Complete 5 missions with the Alliance sentinel squad member
ME1: Complete Eden Prime
ME1: Use biotic Lift 25 times
ME1: Use biotic Throw 25 times
ME1: Use biotic Warp 25 times
ME1: Use biotic Singularity 25 times
ME1: Use biotic Barrier 25 times
ME1: Use biotic Stasis 25 times.
ME1: Use Damping Field 25 times
ME1: Use AI Hacking 25 times
ME1: Use Sabotage 25 times
ME1: Use medi-gel 50 times
ME1: Use Neural Shock 25 times
ME2: Incinerate the armor of 25 enemies
ME2: Hit 20 different targets with multiple biotic powers to combine the effects
ME2: Warp the barriers of 25 enemies
ME3: Call down an orbital strike.
ME3: Disable a group of fighter squadrons.
ME3: Extract ancient technology.
ME3: Defeat an old adversary.
ME3: Send a warning across the galaxy.
ME3: Make the final assault.
ME3: Mission accomplished.
ME3: Deliver most of the Galaxy at War assets to the final conflict.
ME3: Perform any combination of 50 biotic combos or tech bursts.
ME3: Overload the shields of 100 enemies.
ME3: Kill a brute while it's charging you.
ME3: Kill 10 guardians with headshots from the front while their shields are raised.
ME3: Hijack an Atlas mech.
ME3: Stop an out-of-control scheme before it's too late.
ME3: Defeat a group of Spectre-level opponents on Normal, Hardcore, or Insanity.
Complete Mass Effect 1, 2 or 3 on Insanity without changing difficulty
Complete two games in Mass Effect Legendary Edition on Insanity without changing difficulty
Complete all three games in Mass Effect Legendary Edition on Insanity without changing difficulty
Finish Mass Effect 1, 2 and 3 with the same character
Kill 2,000 enemies in Mass Effect 1, 2 or 3
Kill 100 enemies with melee attacks in Mass Effect 1, 2 or 3