No missable achievements (plus 63 unknown)
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Completed the mission "Lost Legion Invasion".
Reached level 5.
Completed the mission "Marooned".
Completed the mission "Systems Jammed".
Reached level 10.
Completed the mission "A New Direction".
Unlocked 10 Customization Items.
Completed the mission "Intelligences Of The Artificial Persuasion".
Used the Grinder to create an item.
Completed the mission "Let's Build A Robot Army".
Completed the mission "Home Sweet Home".
Completed the mission "Science And Violence".
Completed the mission "Watch Your Step".
Opened Zarpedon's Chest.
Completed the mission "Eye To Eye".
Reached level 25.
Defeated the Opha Superior.
Defeated the Empyrean Sentinel.
Won a duel.
Completed 30 side missions.
Completed the mission "To Arms".
Pancaked an enemy in the Stingray.
Revived 10 players with oxygen.
Launched 4 rockets from Elpis.
Digitized into Claptrap's Brain.
Killed 100 enemies with Wolf.
Completed the mission "Return of Captain Chef".
Used the Grinder to create a Legendary item.
Delivered Zarpedon's message.
Had Purple-rated gear or better equipped in every slot.
Defeated the Invincible Empyrean Sentinel.
Discovered all named locations aboard the Helios Space Station.
Destroyed the Tassiter Proxy.
Successfully recovered the Override Key.
Had an enemy frozen, corroded, ignited, and electrocuted at the same time.
Gave the H-Source to Jack.
Reached level 50.
Killed 100 enemies with the Aspis.
Saved the Guardians from the Scav Poachers.
Removed Excalibastard from the stone.
Killed 10 enemies in a single activation of Showdown.
Discovered all named locations in Serenity's Waste, Triton Flats and Stanton's Liver.
Discovered all named locations in Outlands Canyon, Outlands Spur and Vorago Solitude.
While airborne, spun 360 degrees then got a kill with a Sniper Rifle without using the scope.
Completed all of the side missions.
Completed all 5 rounds of The Holodome.
Completed a round using the Mutator.
Looted 10 Moonstone Chests.
Suffocated for 5 continuous minutes without dying.
Tried all the Moxxtails in the Up Over bar in Concordia.
Completed the Badass Round of The Holodome.
Had a Lost Legion Eternal kill 3 of his friends.
Outran the Wheel in the Temple of Boom.
Completed the Badass Round without going into Fight For Your Life.
Discovered all named locations.
Talked to all of Claptrap's Holographic Projections.
Shattered 3 frozen enemies with a single slam attack.
Completed the "Sub-Level 13" missions with 3 other players.
Experienced all Vault Hunter Modes using Vault Hunter.EXE.
Killed 10 SpyBugs before they took your photo.
Experienced all 9 Game Modes and all 9 Modifiers of the Mutator.
Completed level 1 of all challenges with a single character.