If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Your big bulldozer is ready to demolish all the buildings in the area. The game is finished when you get all the achievements. But to do it you should not only demolish buildings but make some tricks. To destroy a building you must bring down the walls to the ground level. If you do it right the building will burn. And don’t forget to clean out heaps of bricks.
Arrows or WASD – move.
Space – boost.
R – respawn.