World thirteen features only normal boxes. It occupies almost the whole game screen.
Step by step solution
From the start position - go UP, then go LEFT, LEFT, LEFT, LEFT, UP, UP, UP,
push LEFT, UP and go LEFT, LEFT and push DOWN.
Go LEFT, LEFT, DOWN, DOWN, DOWN, RIGHT and push RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT.
Go LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, UP, LEFT, LEFT, DOWN and
push RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT. Go UP, RIGHT, then
push DOWN, go LEFT, DOWN and push RIGHT.
Go LEFT, LEFT, UP, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT,
DOWN, DOWN, RIGHT, RIGHT, RIGHT, RIGHT and push UP.
Go DOWN, LEFT, LEFT, LEFT, LEFT, UP, UP, RIGHT, RIGHT, RIGHT and push
RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT.
Now go DOWN, RIGHT, push UP, go LEFT, UP and push RIGHT.
Go DOWN, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, UP, UP, UP, LEFT, UP, LEFT, LEFT, DOWN and push DOWN, DOWN.
Go UP, UP, LEFT, LEFT, DOWN, DOWN, DOWN and RIGHT.
Push RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT.
Now go UP, RIGHT and push DOWN.
Go LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, UP, UP, UP, LEFT and push LEFT.
Now go UP, LEFT and push DOWN, DOWN, DOWN.
Go UP, UP, LEFT, LEFT, DOWN, DOWN, DOWN and RIGHT.
Push RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT.
Go LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, UP, UP, UP, LEFT, LEFT, UP, UP, UP, LEFT.
Now push DOWN, DOWN, DOWN, DOWN, DOWN. Go UP, UP, LEFT, LEFT, DOWN, DOWN, DOWN and RIGHT.
Push RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT
Go DOWN, RIGHT, then push UP, go LEFT, UP and push RIGHT.
Only one box left. Go LEFT, Go DOWN, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, LEFT, UP, UP, UP, LEFT, LEFT,
UP, UP, UP and RIGHT.
Push DOWN, DOWN, go LEFT, DOWN, LEFT, DOWN, DOWN, DOWN, RIGHT, RIGHT, RIGHT, UP, UP, UP and push LEFT, LEFT.
Now go UP, LEFT and push DOWN, DOWN, DOWN.
Go UP, UP, LEFT, LEFT, DOWN, DOWN, DOWN and RIGHT.
Push RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT and RIGHT.
Congratulations. You have completed the thirteenth world. Get ready for the fourteenth.