Click on Play Now and then the big green button to play on the first stage. If this isn't your first time, you can use the blue button on the right side of the screen to choose between the tracks you've already done.
Once the game starts, your car is a-runnin'! The gas is always on max, so it's your job to control your car's left and right turns and so guide it around. With a mouse, you can click and hold on any side of the screen (left or right) to change the direction the car is going. If you are using a touch screen, you can use your finger to touch the left or right side of the screen to do the same.
Collect stars for points, collect power ups to use on your enemies (automatically) and finish the race in the best time you can!
Watch out for other cars bumping into you, or you may lose the stars you've collected!