Here is the full list of all 51 Injustice: Gods Among Us Ultimate Edition trophies - there are 38 bronze, 10 silver, 2 gold and 1 platinum.
Win all story mode minigames
Complete Classic Battle with all characters
Perform a 10 hit combo with every character
Perform every character's supermove
Complete 100% of Story Mode
Dethrone the King in an online match
Defeat a Survivor
Enter Online Practice with someone on your friends list
Vote Correctly in a KOTH match
Complete 50% of Story Mode
Perform 8 throws and win in a multiplayer match
Make a comeback when at low health (10% or less)
Win a Clash sequence with any character
Cause maximum damage in all Arenas (does not include Practice mode)
Enter Practice Mode
Complete Classic Battle with any character
Win 1 complete Ranked match
Win a single online match
Get 3 stars on 1 S.T.A.R. Lab Mission
Complete 1 S.T.A.R. Lab Mission
Win a match with the super move of any character
Complete Tutorial
Win with Batman using every special move and his Supermove
Knock opponent through all transitions across all levels
Unlock a costume in the Archives
Unlock All costumes in the Archives
Equip a new Character Portrait
Equip a new Background Image
Equip a new Icon
Win a multiplayer match with a timeout
Defeat every Villain With Batman
Send an opponent through all three Metropolis transitions in one fight
Reach Level 10
Use every interactable and win in a multiplayer match
Knock an opponent through a transition
Win a match with Green Arrow using only arrows
Win a match as Deathstroke without missing a shot (minimum 12 shots)
View Your Hero Card
You've unlocked all Trophies!
Complete Battle Mode
Beat All S.T.A.R. Lab Missions (Excluding DLC)
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 every special move of every character
Perform every Meter Burn special move of every character
Perform every level interaction once
Unlock everything in the Archives