The premise of the bus simulator games is simple!
You have various controls that you can use to drive the bus and get it to the finish line before the gas runs out.
There is a steering wheel that you can use to control and steer the bus. There is a small accelerator on the side that you have to hold continuously in order to proper the bus forward and there is a button right next to it to stop the bus. The game ends if you run out of gas or if the bus is severely damaged and not able to move!