World four hundred and thirty-one is with half of the boxes already placed.
Step by step solution
Go DOWN, RIGHT, RIGHT and push UP. Go DOWN, RIGHT, RIGHT, RIGHT, UP, UP, LEFT, LEFT and push DOWN. Go UP, RIGHT, RIGHT, DOWN, DOWN, LEFT and push UP. Go LEFT, UP, UP, LEFT, LEFT, LEFT, UP, UP, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, DOWN, push DOWN and DOWN.
Push LEFT, go RIGHT, UP, push LEFT and LEFT. Go RIGHT, RIGHT, UP, UP, LEFT, LEFT and push DOWN. Go UP, RIGHT and push DOWN.
Go UP, LEFT, LEFT, LEFT, LEFT, DOWN, DOWN, RIGHT, push UP, go LEFT, UP, push RIGHT, RIGHT, RIGHT, go DOWN, RIGHT, RIGHT, UP, push LEFT and LEFT.
Go RIGHT, RIGHT, DOWN, DOWN, DOWN, LEFT, DOWN, DOWN, RIGHT, push UP and UP. Go DOWN, LEFT, LEFT, LEFT, DOWN, LEFT, LEFT, UP, push RIGHT and RIGHT.
Congratulations. You have completed world four hundred and thirty-one. Get ready for world four hundred and thirty-two.