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.
Collected every treasure item.
Spirit-bended 200 dark spirits.
Collected 10 cabbages.
Purchased 12 talismans.
Completed the game on Extreme difficulty.
Went into Avatar State 10 times.
Maxed out all bending types.
Obtained all combos.
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.
Completed Chapter 7.
Performed 100 Finishing Moves.
Completed Chapter 6.
Completed Chapter 5.
Dodged 100 times.
Countered 100 times.
Went into Clash Mode 10 times.
Completed Chapter 4.
Jumped 100 times.
Completed a Naga Running sequence without hitting anything.
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.
Completed Chapter 1.