Here is the full list of all 24 Klang achievements.
Defeat Bazz.
Master all Shufflejumper tracks.
Listen to a song in the Pirate Bay.
Make it out of the forest.
Go the wrong way...
Finish the prologue.
Find a pirate token.
Score a 9x multiplier.
Score your first S rank.
Score your first SSS rank.
Unlock all pirated music!
Dodge Sonus' beam during the prologue.
Defeat Sonus during the prologue.
Listen to the last song on the list in the Pirate Bay.
Survive the Death Angel encounter.
Defeat Sonus.
Survive the Limbo encounter
Welcome to the end!
SSS rank it all!
Finish with a track score of 250 or higher!
Finish with 0 deaths!
Finish using the fastest path possible!
Finish in less than 1 hour with a 150+ track score!
Master Shufflejumper 4 early by riding the wind.