If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Cranes have a lot of utilities and today you are going to explore and exciting one: destroying buildings! Drive your crane with care and deliver a bomb next to the building you want to destroy. Make sure you get out of the way when it explodes so you will not damage your crane. Then clean up the debris from the street and take it to the collection center. Destroy two buildings before the time runs out in order to win the game. Have a blast!