Here is the full list of all 50 Injustice: Gods Among Us Ultimate Edition achievements.
Win 1 complete Ranked match
Defeat every Villain With Batman
Win a match as Deathstroke without missing a shot (minimum 12 shots)
Perform every character's supermove
Defeat a Survivor
Dethrone the King in an online match
Enter Online Practice with someone on your friends list
Win with Batman using every special move and his Supermove
Cause maximum damage in all Arenas (does not include Practice mode)
Enter Practice Mode
Send an opponent through all three Metropolis transitions in one fight
Perform 8 throws and win in a multiplayer match
Complete Classic Battle with any character
Win a match with Green Arrow using only arrows
Unlock a costume in the Archives
Unlock All costumes in the Archives
Get 3 stars on 1 S.T.A.R. Lab Mission
Complete 1 S.T.A.R. Lab Mission
Complete 100% of Story Mode
Complete 50% of Story Mode
Vote Correctly in a KOTH match
Knock an opponent through a transition
Complete Tutorial
Win a single online match
Win a multiplayer match with a timeout
Equip a new Icon
Reach Level 10
Win a match with the super move of any character
Win a Clash sequence with any character
Equip a new Background Image
Equip a new Character Portrait
View Your Hero Card
Complete Classic Battle with all characters
Complete Battle Mode
Use every interactable and win in a multiplayer match
Beat All S.T.A.R. Lab Missions (Excluding DLC)
Win all story mode minigames
Reach Level 100
Win 100 complete Online Matches
Play 200 complete Online Matches
Win 10 complete Ranked matches
Get 100 Stars in S.T.A.R. Lab Mode
Complete All S.T.A.R. Lab Missions with 3 Stars
Perform a 10 hit combo with every character
Knock opponent through all transitions across all levels
Perform every special move of every character
Perform every Meter Burn special move of every character
Perform every level interaction once
Make a comeback when at low health (10% or less)
Unlock everything in the Archives