Here is the full list of all 31 The Legend of Korra trophies - there are 12 bronze, 14 silver, 4 gold and 1 platinum.
Got all other trophies.
Completed all tutorials.
Spirit-bended 200 dark spirits.
Collected every treasure item.
Went into Avatar State 10 times.
Purchased 12 talismans.
Completed the highest difficulty of Pro-bending.
Won a Face-Off in a Pro-bending match.
Completed the game on Extreme difficulty.
Got 10 knock-outs in Pro-bending matches.
Maxed out all bending types.
Obtained all combos.
Performed 100 Finishing Moves.
Countered 100 times.
Collected 10 cabbages.
Completed a Naga Running sequence without hitting anything.
Completed Chapter 8.
Completed Chapter 7.
Completed Chapter 6.
Completed Chapter 5.
Dodged 100 times.
Went into Clash Mode 10 times.
Used your first equipped item.
Completed Chapter 4.
Completed Chapter 3.
Jumped 100 times.
Equipped your first item on the Korra's Room.
Bought your first item at the shop.
Entered the Collection Screen for the first time after finding a treasure.
Completed Chapter 2.
Completed Chapter 1.