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