Summary
It's time for a confession. If you're like me, a programmer, that means you're probably sitting in a room with a bunch of books like this one behind you. Of those books, you've probably only opened half of them, and you've probably only read one or two of them cover-to-cover. Harry Potter notwithstanding.
Great news! At this point, you've made an endless runner. It's got no sound, the collision boxes are pretty big (have you tried to go under a platform yet?), and there's no menu system, but at this point, you have a game. You have the skeleton to make it more fun as you play around, and you're welcome to use this to make even larger or completely different endless runners. I wouldn't hold it against you if you stopped following along at this point, because you've learned a ton.
But if you do decide to stick around for the next chapter, we'll be adding a requirement for immersion that's required for any...