Here is the full list of all 19 Juju achievements.
Defeat Calypso.
Complete all unlockable levels.
Gather every Coin in the game.
Find all secret teleports.
Defeat Cobos and collect his key part.
Unlock all skills.
Make 4 enemies dance at once.
Defeat Octobos and collect his key part.
Defeat Robos and collect his key part.
Hit 3 enemies with one dash.
Complete any level without collecting an amber.
Complete one unlockable level.
Defeat Frobos and collect his key part.
Unlock a new skill.
Complete any level without losing a heart.
Find a secret teleport.
Complete a level in co-op.
Gather all Coins on one level.
Collect more than 100% of ambers in any level.