Here is the full list of all 39 Rainbow Billy: The Curse of the Leviathan achievements.
Raise 40 creatures' friendships to Level 3!
Raise ALL creatures' friendships to Level 3!
Catch at least one of each kind of fish!
Own 500 coins or more.
Break the Curse of the Leviathan and save the World.
Climb to the highest point in each area of the World.
Befriend all creatures.
Accept your other self and befriend Shadow Billy.
Peek through the window...
Hear each and every one of the The Confessor's secrets.
Get reprimanded for punching barrel-kind.
Collect ALL Thought Upgrades!
Collect 75 Thoughts.
Raise 30 creatures' friendships to Level 2!
Fast travel between two distant areas of the World.
Glide using the Billy-Copter for more than 5 straight seconds!
Face your fears and befriend Calypso.
Talk to all Kickstarter Backers characters!
Raise 20 creatures' friendships to Level 3!
Collect 50 Thoughts.
Discover the broken warp pipe.
Flawlessly complete a difficult "Dodge" attack minigame!
Catch 10 non-gummi items while fishing.
Fight toxic masculinity and befriend Dragalant.
Collect 25 Thoughts.
Dig up 15 buried treasures.
Flawlessly complete a difficult "Paddle" attack minigame!
Flawlessly complete 50 attack minigames!
Discover Disco Broccoli!
Recolor five colors in one blow!
Flawlessly complete a difficult "Circle" attack minigame!
Collect 10 Thoughts.
Raise 5 creatures' friendships to Level 2!
Catch three different objects in one fishing session!
Flawlessly complete a difficult "Slots" attack minigame!
Flawlessly complete a difficult "Line" attack minigame!
Destroy 25 Objects!
Convert a Thought into a Figment of Imagination!Service.
Listen to Friend-Ship whistle for more than 5 straight seconds.