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