World twenty looks hard at the beginning, but it is not hard at all.
Step by step solution
From the initial position, push DOWN, go LEFT, push LEFT, go DOWN, push LEFT and UP.
Go RIGHT, RIGHT, RIGHT, RIGHT, RIGHT and push RIGHT. Go UP, UP, RIGHT, RIGHT, DOWN, DOWN, push LEFT, LEFT, LEFT, DOWN, DOWN and LEFT.
Go RIGHT, UP, UP, RIGHT, UP, UP, RIGHT, push DOWN, go RIGHT, DOWN, LEFT, UP, LEFT and push DOWN.
Congratulations. You have completed the twentieth world. Get ready for world twenty-one.