Here is the full list of all 39 Planet of Mubu achievements.
Start the game!
Complete The Tutorial Zone!
Complete The Forest Zone!
Complete The Puzzle Zone!
Complete The Arena Zone!
Complete The Run Zone!
Complete The Viking Zone!
Complete The Maze Zone!
Complete The Boss Zone!
Find the blue cube!
Find the red cube!
Find the green cube!
Find A!
Find B!
Find C!
Find D!
Find E!
Find F!
Find G!
Find H!
Find I!
Find J!
Find K!
Find L!
Find M!
Find N!
Find O!
Find P!
Find Q!
Find R!
Find S!
Find T!
Find U!
Find V!
Find W!
Find X!
Find Y!
Find Z!
Destroy the world!