missing code

[KK4HFJ]

two lines of missing code.
very first line:
import pgzrun
very last line:
pgzrun.go()

now "python pipemania.py" works.

[Scubadooper]

I found that code wasn't needed

[dww100]

The code is not needed if you run using:

pgzrun PipeMania.py

If however you want to run in the way @KK4HFJ shows then it is. I think this is more a documentation than code issue.

[SheetLightning]

Yes, the assumption is being made that the user is familiar with pgzero knows how to run the code. I was just getting 'Hello from the pygame community.' until I read this issue and added those lines.

Thre is also an error in the printed version in line 20. The part '_path.png' should be '_way.png'.