This is super minor, but I would find it helpful if the folders in the zip file containing sample code had the chapter number at the front. Instead of CreatingScenesWithSpritesAndNodes perhaps 1-CreatingScenesWithSpritesAndNodes or Ch1-CreatingScenesWithSpritesAndNodes. Then the folders would sort in order and the resources/code would be easier to find.
The current chapter name is printed at the top of every other page, so it’s not that hard to figure out what folder the current code/resources are in. But I am finding myself jumping back to the folders for the previous chapter, or the next chapter, now and then and I have to check the table of contents to get the chapter title before I can do so.