Here is the full list of all 12 Juice Galaxy achievements.
J is for Juice!
Equip the grappling plunger
Defeat Ingot
Defeat Mrs. Slitherss
Defeat Mr. Fox
Defeat the Creator
Defeat Sgt. Suckerpunch
Defeat the Clog
Defeat the Wawsp Queen
Defeat the Dream Eater
Equip the Wawsp Queen's Head
Obtain juice drinking powers