World three hundred and ninety-eight is with two misplaced boxes.
Step by step solution
Go LEFT, LEFT, LEFT, push DOWN, go LEFT and push LEFT. Go RIGHT, DOWN and push RIGHT. Go DOWN, RIGHT, RIGHT, UP and push UP. Go DOWN, DOWN, LEFT, LEFT, UP, UP, UP, RIGHT, UP, RIGHT, RIGHT, DOWN, push LEFT, LEFT, go UP, LEFT and push DOWN. Go RIGHT, RIGHT, RIGHT, RIGHT and push DOWN. Push RIGHT, go DOWN, DOWN, LEFT, push UP and UP.
Go RIGHT, UP, push LEFT, LEFT, LEFT and LEFT. Go RIGHT, RIGHT, RIGHT, RIGHT, DOWN, DOWN, DOWN, RIGHT, RIGHT, UP, RIGHT, UP, UP, LEFT and push DOWN. Push LEFT and LEFT. Go DOWN, DOWN, RIGHT, RIGHT, push UP, go RIGHT, UP and push LEFT. Go DOWN, DOWN, LEFT, LEFT, LEFT, UP, push UP, go RIGHT, UP, push LEFT and LEFT.
Go UP, LEFT, LEFT, DOWN, push RIGHT, go DOWN, push RIGHT and RIGHT. Go LEFT, LEFT, UP, UP, RIGHT, push DOWN, go LEFT, DOWN and push RIGHT. Go LEFT, DOWN, DOWN, LEFT, LEFT, UP and push RIGHT. Push UP, go DOWN, DOWN, RIGHT, push UP, go LEFT, UP and push RIGHT. Go UP, UP, LEFT, push DOWN, DOWN, go RIGHT, DOWN, DOWN, LEFT, LEFT, UP and push RIGHT.
Go DOWN, RIGHT, push UP and UP. Go LEFT, DOWN, LEFT, LEFT, UP, push RIGHT and RIGHT. Go UP, UP, RIGHT, RIGHT, DOWN and push LEFT. Go UP, LEFT, LEFT and push DOWN. Push RIGHT, go DOWN, DOWN, LEFT, LEFT, UP and push RIGHT. Go LEFT, LEFT, UP, LEFT, LEFT, DOWN, push RIGHT, RIGHT and RIGHT. Go DOWN, RIGHT, RIGHT and push UP. Push LEFT, go UP, UP, RIGHT and push DOWN. Go UP, RIGHT, RIGHT, DOWN, push LEFT, LEFT, go UP, LEFT and push DOWN.
Congratulations. You have completed world three hundred and ninety-eight. Get ready for world three hundred and ninety-nine.