World one hundred and fourty-six is with very tall compartment for the slots.
Step by step solution
Go UP, RIGHT, UP, UP, UP, UP, UP, UP, LEFT, UP, LEFT, LEFT, LEFT, LEFT, LEFT, push DOWN, DOWN and DOWN. Go RIGHT, DOWN, push LEFT, LEFT, LEFT, go DOWN, LEFT, push UP and UP.
Go DOWN, DOWN, RIGHT, DOWN, RIGHT, RIGHT and push RIGHT. Go DOWN, push LEFT, LEFT, LEFT, go UP, LEFT and push DOWN.
Go RIGHT, RIGHT, RIGHT, RIGHT, DOWN, RIGHT, RIGHT, UP, push LEFT, LEFT, LEFT, LEFT, go UP, LEFT and push DOWN.
Go RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, UP, push LEFT, LEFT, LEFT, LEFT, go DOWN, LEFT, push UP, UP, UP and UP.
Go DOWN, RIGHT, RIGHT, UP, UP, UP, RIGHT, UP, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, DOWN, DOWN, DOWN, LEFT, LEFT, LEFT, push LEFT and LEFT. Go RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, UP, UP, LEFT, UP, LEFT, LEFT, LEFT, LEFT, DOWN and push DOWN. Go LEFT, push DOWN, DOWN, DOWN, go LEFT, DOWN, DOWN, RIGHT, RIGHT, UP, push LEFT, LEFT, LEFT, go DOWN, LEFT, push UP, UP and UP.
Go RIGHT, RIGHT, RIGHT, UP, UP, RIGHT, UP, UP, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, DOWN, DOWN, DOWN, LEFT, LEFT, LEFT, LEFT and push LEFT. Go UP, LEFT, push DOWN, go RIGHT, DOWN, push LEFT, LEFT, go DOWN, LEFT and push UP.
Go RIGHT, RIGHT, RIGHT, UP, UP, UP, UP, RIGHT, RIGHT, DOWN, push LEFT and LEFT. Go UP, LEFT, push DOWN, DOWN, DOWN, go RIGHT, DOWN, push LEFT, LEFT and LEFT.
Go RIGHT, RIGHT, RIGHT, UP, UP, UP, RIGHT, RIGHT and push DOWN. Go UP, UP, RIGHT, RIGHT, DOWN, RIGHT, DOWN, DOWN, LEFT, LEFT, push LEFT, LEFT and LEFT. Go UP, LEFT, push DOWN, go RIGHT, DOWN, push LEFT and LEFT.
Go RIGHT, RIGHT, UP, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, UP, UP, LEFT and push DOWN. Go RIGHT, DOWN, push LEFT, LEFT, LEFT, LEFT, LEFT, go UP, LEFT, push DOWN, DOWN, DOWN, go LEFT, DOWN, DOWN, RIGHT, RIGHT, UP, push LEFT, LEFT, LEFT, go DOWN, LEFT and push UP.
Go RIGHT, RIGHT, RIGHT, UP, UP, UP, UP, UP, UP, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, DOWN, push LEFT, LEFT, LEFT, LEFT, go UP, LEFT, push DOWN, DOWN, DOWN, DOWN, DOWN, go LEFT, DOWN, DOWN, RIGHT, RIGHT, UP, push LEFT, LEFT, go DOWN, LEFT and push UP.
Go RIGHT, RIGHT, UP, UP, RIGHT, UP, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, DOWN, DOWN, DOWN, DOWN, LEFT, push LEFT, LEFT, LEFT, LEFT, LEFT, LEFT and LEFT.
Go RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, UP, UP and push LEFT. Push DOWN, go RIGHT, DOWN, push LEFT, LEFT, LEFT, LEFT, LEFT, go DOWN, LEFT and push UP. Go RIGHT, UP, push LEFT, LEFT and LEFT.
Go RIGHT, RIGHT, RIGHT, RIGHT, RIGHT, DOWN, RIGHT, RIGHT, RIGHT, UP, UP, UP, UP, LEFT, push DOWN, DOWN, DOWN, go RIGHT, DOWN, push LEFT, LEFT, LEFT, LEFT, LEFT, LEFT and LEFT.
Go RIGHT, RIGHT, RIGHT, RIGHT, UP, UP and push RIGHT. Go LEFT, DOWN, DOWN, RIGHT, RIGHT, RIGHT, UP, UP, UP, LEFT, push DOWN, DOWN, go RIGHT, DOWN, push LEFT, LEFT, LEFT, LEFT, LEFT, go DOWN, LEFT, push UP, go RIGHT, UP, push LEFT and LEFT.
Congratulations. You have completed world one hundred and fourty-six. Get ready for world one hundred and fourty-seven.