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