World twenty-nine seems hard at the beginning but after some trial and error is easy to solve.
Step by step solution
First go UP, push RIGHT, go LEFT, DOWN and DOWN. Push RIGHT and UP. Go RIGHT, push RIGHT, go DOWN, push LEFT, go RIGHT and DOWN.
Go RIGHT, RIGHT, UP, push LEFT and LEFT. Go UP, UP, UP, RIGHT, RIGHT and DOWN. Push LEFT and DOWN.
Go LEFT, DOWN, DOWN, RIGHT, RIGHT and UP. Push LEFT, go UP, LEFT, LEFT, LEFT, LEFT, UP, UP and RIGHT.
Push DOWN, go LEFT and DOWN. Push RIGHT and RIGHT.
Go LEFT, LEFT, DOWN, DOWN and RIGHT. Push UP, go LEFT, UP and push RIGHT.
Congratulations. You have completed world twenty-nine. Get ready for world thirty.