Challenges

Now it's yours. Change one thing at a time, run it, and see what happens.

1. Change BG_COLOR to a different colour. Can you make the background white?
2. Make Bob twice as fast by changing BOB_SPEED. Then make him very slow.
3. Make Bob bigger or smaller with BOB_RADIUS. What happens to the arrow?
4. Change WIDTH and HEIGHT to make a tall, thin window.
5. Give Bob blonde hair, then green skin.
6. Make the arrow longer by changing the 18 in tip.
7. Make the game use the arrow keys instead of W A S D. Hint: look for pygame.K_UP.
8. Change the FPS to 10. Does Bob still move at the same speed? Why?

Have fun with it, and send me what you build.