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