Here is the full list of all 18 Baba Is You achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Complete a secret area.
Complete the world map.
Really beat the game.
Complete the abstract area.
Complete the garden.
Complete the cavern.
Complete the mountain.
Complete the forest.
Complete the space area.
Find an orb.
Complete the solitary isle.
Complete the forest of fall.
Complete the ruins.
Beat the game.
Complete the lake.