Here is the full list of all 28 MAGICALSPIRAL achievements.
Don't use any items.
Never retry from a game over.
Kill 50% of all monsters.
Get up to a 10-hit combo.
Win the fight against Flower Golem.
Win the fight against Haokah.
Win the fight against Sylph.
Win the fight against Undine.
Win the fight against Salamander.
Win the fight against Sobel.
Find the gold chest in Sobel's Stage 1.
Find the gold chest in Sobel's Stage 2.
Find the gold chest in Sobel's Stage 3.
Find the gold chest in Sobel's Stage 4.
Find the gold chest in Sobel's Stage 5.
Win the fight against Medianne.
Defeat the Selector as Medianne.
Defeat the Selector as Sobel.
Avoid all the rocks in Collapsing Cave.
Avoid all the lightning in Thunder and Lightning.
Defeat a number of monsters in Going For A Swim.
Don't open a single chest.
Collect every chest.
Don't kill any non-boss monsters.
Kill every monster.
Get up to a 30-hit combo.
Beat any route within 30 minutes.
Get up to a 50-hit combo.