Full list of all 48 Young Justice: Legacy achievements worth 1,000 gamerscore. It takes around 20-25 hours to unlock all of the achievements on Xbox 360.
Complete all missions in co-op mode
Reach level 40
Complete 10 missions co-op mode
Complete 5 missions co-op mode
Complete 1 mission co-op mode
Complete all challenges
Get all A Grades in YJ Challenges
Buy all enhancements
Use all the powers of the heroes
Get 50% A Grades in YJ Challenges
Complete half of the challenges
Complete the game on Hard Difficulty
Unlock all characters
Activate Squad Boost 20 times
Don’t break any Statue in the Museum Stage during “A Hostage Crisis”
Buy half of the enhancements
Complete 1 challenge
Don't activate the Statues in The Warriors Stage during “Tag Team”
Escape the Avalanche Stage during “Go with the Flow” in less than 5 minutes
Collect all the Alternate Costumes
Avoid search light in Gotham Docks
Get all the Dioramas
Get all Red Arrow Journals
Reach a Score of 5000 in the YJT
Answer 5 Young Justice Trivia questions correctly in a row
Reach a Score of 500 in the YJT
Reach a Score of 1000 in the YJT
Obtain A Grades in all Missions
Finish the game
Defeat Blockbuster
Reach level 20
Defeat The Riddler
Defeat Psimon
Defeat Black Manta
Obtain A Grades in half of the Missions
Avoid damage from the spike trap in Atabey's Temple Stage during “The Goddess Shrine”
Defeat Bane
Get half the Dioramas
Collect half of the Alternate Costumes
Defeat Icicle Jr and Sportmaster
Destroy 350 objects
Defeat Killer Frost
Reach level 10
Defeat 500 enemies
Defeat Sportmaster
Defeat Cheshire
Defeat 200 enemies
Defeat the first 15 enemies