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