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 mountain.
Complete the cavern.
Complete the garden.
Complete the forest.
Complete the solitary isle.
Really beat the game.
Complete the world map.
Complete the abstract area.
Beat the game.
Complete the space area.
Find an orb.
Complete the forest of fall.
Complete the ruins.
Complete the lake.