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