Here is the full list of all 12 Krinkle Krusher achievements.
Show who's the best by defending the castle!
Complete every stage with 3 stars and get all magical gems.
Imprison the King Krinkle forever!
Upgrade the 5 elemental rings to level 5.
Defeat the Kranium Krinkle.
Defeat the Mecha Krinkle.
Knock back the King with spikes and tornados.
Feed Kranium with some spicy krinkles!
Knock back the Mecha Krinkle with his own bomb.
Get all spells.
Use an elemental krinkle explosion to kill 4 other krinkles
Unlock the workshop