The Joker has trapped Batman between two skyscrapers. He is throwing all kinds of construction material on the head of the Dark Knight.
Use the falling concrete blocks and metal beams to climb to the top of the buildings. Think ahead and plan your movements so that the blocks fall in places that are useful to you.
You can briefly cling to walls and surfaces: use those skills to get momentum in your jumps! Watch out for the gas bomb that the Joker will soon throw at you: if you breathe the poison, the game is over.
Use the arrow up to make Batman jump, the left and right arrows to move Batman and R to restart the game.