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