Here is the full list of all 21 Before the Echo achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
See the hidden ending.
Discover the name of she who controls fate.
Learn all spells.
Synthesize Iridium.
Synthesize every recipe in the game.
Beat the game on any difficulty.
Obtain every droppable item in the game at least once.
Defeat an enemy on the seventh floor using only Arclight.
Defeat an enemy using only poison spells.
Defeat an enemy with less than one second remaining on the clock.
Trigger Boost a Trigger Boost.
Defeat an enemy within eleven seconds.
While learning a spell, achieve 100% accuracy for the entire song.
Get her back.
Queue up five spells in a row.
Successfully complete a synthesis at 25% odds of success or lower.
Recover over 150 mana in a single battle, and win.
Defeat the Holiday Whompa.
Obtain all three droppable items from any single enemy.
Complete a battle without failing a spell.
Successfully defeat your first enemy.