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