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