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