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