Here is the full list of all 30 The Legend of Korra achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Got 10 Knockouts in Pro-bending matches.
Completed Chapter 6.
Obtained all combos.
Performed 100 Finishing Moves.
Completed a Naga Running sequence without hitting anything.
Completed Chapter 8.
Countered 100 times.
Won a Face-Off in a Pro-bending match.
Completed all tutorials.
Completed Chapter 7.
Went into Clash Mode 10 times.
Dodged 100 times.
Completed Chapter 5.
Entered the Collection Screen for the first time after finding a treasure.
Completed Chapter 4.
Jumped 100 times.
Completed Chapter 3.
Used your first equipped item.
Equip your first item in Korra's Room.
Bought your first item at the shop.
Completed Chapter 2.
Completed Chapter 1.
Completed the game on Extreme difficulty.
Maxed out all bending types.
Purchased 12 talismans.
Collected every treasure item.
Spirit-bended 200 dark spirits.
Went into Avatar State 10 times.
Completed the highest difficulty of Pro-bending.
Collected 10 cabbages.