Greetings!
I see quite often around these parts and in further fields, that there are constantly people who are just starting out asking how to add networked multiplayer functionality to their HTML5 games. I was one of them, and I hated the near absence of practical explanations that were written in concise, plain-English, yet still detailed, of how to get started.
So, I made a simple game example/template using Socket.io and Phaser, and documented the hell out of it. Almost everything gets a few lines of comments to explain what is doing what, and I haven't assumed any prior knowled