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.
Defeat Octobos and collect his key part.
Make 4 enemies dance at once.
Defeat Robos and collect his key part.
Complete one unlockable level.
Complete any level without collecting an amber.
Defeat Frobos and collect his key part.
Unlock a new skill.
Complete a level in co-op.
Hit 3 enemies with one dash.
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.