Here is the full list of all 24 World End Echo achievements.
Defeat Mellu
Defeat Hilda
Defeat Tara
Defeat Vesta
Defeat Octavia
Defeat Deya
Defeat Lexa
Defeat Angel
Defeat Ashley
Defeat Mirai
Complete the Tutorial
Survive in the Maze
Dodge the Gift of Goddess
Escape from Deya
Steal Pegasus
Destroy 50 stones
Destroy 40 chains
Destroy 100 lotus
Exsplode 100 bombs
Summon 30 lightning bolts
Die 10 times
Die 30 times
Beat 14 levels without dying
Beat the game without dying