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