Here is the full list of all 51 Disgaea 4: A Promise Unforgotten trophies - there are 42 bronze, 5 silver, 3 gold and 1 platinum.
Complete all other trophies. You have obtained all the trophies.
Collect all of the Pirate Ship parts.
Collect all items (excluding grades). Now aim for completing all the grades, too!
Watch all of the special skills.
Unlock all Evil Symbols.
Inflict 10,000,000,000 damage.
Defeat Pringer X: Roar in the Land of Carnage.
Increase an item up to LV 300.
Explode ten Prinnies in a row.
All ranks of all job and monster classes can be created through Character Creation.
Open all chests at the base from Episode 1 to Post-Game.
Defeat God (self-proclaimed) and watch the ending.
Watch Emizel's epilogue.
Watch Desco's epilogue.
Watch Fuka's epilogue.
Watch Fenrich's epilogue.
Visit the Land of Carnage.
Clear all of the X-Dimension maps.
Enforce discipline 100 times.
Defeat Prinny Kurtis in the Post-Game and make him an ally.
Defeat Zetta in the Post-Game and make him an ally.
Train an ally up to LV 9999.
Steal 10 Rare and/or Legendary items.
Fight five battles with the "Classic" display option. Pixels still rock!
Give 50 bribes.
Defeat Asagi in the Post-Game and make her an ally.
Defeat Laharl in the Post-Game and make him an ally.
Defeat 100 Pirate Crew members in the Item World.
Accidentally destroy Axel's statue in the Mystery Room.
Defeat Etna in the Post-Game and make her an ally.
Inflict 100,000 damage.
Defeat Raspberyl in the Post-Game and make her an ally.
Get over 100,000,000 HL.
Conduct your first Reverse Pirating.
Max out the Rosen Queen Company customer level.
Defeat Archangel Flonne in the Post-Game and make her an ally.
Open 100 treasure chests.
Defeat Axel in the Post-Game and make him an ally.
Clear the main game and unlock the Post-Game.
Watch Artina's epilogue.
Persuade by force three times. Demons should always resort to violence!
Clear up to Episode 7 in the main story.
Cancel 1,000 battle actions.
Conduct your first Map Edit.
Defeat an ally character.
Reincarnate for the first time.
Clear up to Episode 3 in the main story.
Throw and capture an enemy character in the base panel.
Clear 30 floors in the Item World.
Get a Game Over from having your party get defeated.
Watch the opening anime. Enjoy Disgaea 4!