Full list of all 65 LEGO Marvel's Avengers achievements worth 1,250 gamerscore. It takes around 35-40 hours to unlock all of the achievements in the base game.
The base game contains 40 achievements worth 1,000 Gamerscore, and there are 5 DLC packs containing 25 achievements worth 250 Gamerscore.
Completed 'Earth's Mightiest'
Turned on all Red Brick Extras at the same time
Visited all Hub locations
Transformed into Stan Lee (Hulkbuster)
Played as Captain Britain, Union Jack, Spitfire, Agent Carter and Mandarin (Trevor Slattery)
Played as: Hawkeye (Kate Bishop), Hulkling, Wiccan, America Chavez and Speed in the same session
Played as every Iron Man variant in one session
Died and respawned while playing as Aldrich Killian
Played as Harley Keener and Tony Stark in any level other than level 9
Completed 'Ready A.I.M. Fire'
Played as any version of Falcon and as any version of Cap, while in Washington D.C.
Played as Iron Fist, Daredevil, Jewel (Jessica Jones) and Luke Cage
Created and play as a Custom Character equipped with Mjolnir
Completed 'Lack of Insight'
Grew Ant-Man, Black Goliath, and Fin Fang Foom in one sitting
Transformed from Lou Ferrigno to Hulk (Lou Ferrigno)
Played as Fandral, Hogun and Volstagg in one sitting
Played as Moon Knight, Moondragon and Moon Boy in one session
Played as Vision - both playable characters
Teamed up Nick Fury and Quicksilver
Completed 'Ultron Undone'
Completed 'Rise of Ultron'
Completed 'Korea Prospects'
Completed 'Anger Management'
Completed 'No Strings On Me'
Completed 'Lost in the Aether'
Stopped 10 random crimes in Manhattan during a single session
Drove Lola as Agent Coulson
Completed 'Avengers Assemble'
Transformed from Banner to Hulk
Completed 'Helicarrier Havoc'
Created a Custom Character
Completed 'Shakespeare in the Park'
Completed 'Rail Hydra'
Completed 'A Loki Entrance'
Died and respawned while playing as Coulson
Completed 'Struck Off the List'
Achieved True Avenger in any level
Witness the 100% Stud Fountain inside Avengers Tower
Unlock and view all 15 Minikit Comic Pages
Set both Free Play characters as the Enchantress and Executioner in the Asgard hub area
Complete the 'The Masters of Evil' level
Complete the 'The Masters of Evil' level with all Minikits unlocked
Complete the 'The Masters of Evil' level after achieving True Avenger status
Defeat 20 enemies as the Black Knight (Dane Whitman) during Free Play
Set both Free Play characters as Tic and Hawkeye (Classic)
Flew the Captain Marvel Skycycle as Captain Marvel in the Manhattan hub
Complete the 'Classic Captain Marvel' level
Complete the 'Classic Captain Marvel' level with all Minikits unlocked
Complete the 'Classic Captain Marvel' level after achieving True Avenger status
Completed the 'Classic Black Panther' level
Completed the 'Classic Black Panther' level after achieving True Avenger status
Complete the 'Classic Black Panther' level with all Minikits unlocked
Complete any race in the HUB using the Black Panther Skycycle
Defeat 20 enemies as Killmonger in the 'Classic Black Panther' level during Free Play
Set both Free Play characters as Baron Mordo and Dormammu
Complete the 'All-New All-Different Doctor Strange' level
Complete the 'All-New All-Different Doctor Strange' level with all Minikits unlocked
Complete the 'All-New All-Different Doctor Strange' level after achieving True Avenger status
Find a way to freeze Doctor Voodoo during Free Play in any area of the game
Set both Free Play characters as Agent Leo Fitz and Agent Jemma Simmons
Flew ''The Bus'' vehicle as Agent Melinda May
Complete the 'MARVEL's Agents of S.H.I.E.L.D.' level
Complete the 'MARVEL's Agents of S.H.I.E.L.D.' level with all Minikits unlocked
Complete the 'MARVEL's Agents of S.H.I.E.L.D.' level after achieving True Avenger status