World four hundred and thirty-nine is very easy puzzle with three ice boxes and one hidden slot.
Step by step solution
Go LEFT, UP, UP and push RIGHT. Go LEFT, DOWN, DOWN, RIGHT and push UP.
Go RIGHT, RIGHT, RIGHT, UP, UP, LEFT, LEFT, push DOWN, DOWN, DOWN, DOWN, go LEFT, DOWN and push RIGHT.
Go UP, UP, UP, RIGHT and push UP.
Go DOWN, push DOWN, go LEFT, DOWN and push RIGHT.
Congratulations. You have completed world four hundred and thirty-nine. Get ready for world four hundred and fourty.