This index is pretty lo-fi. I've spent a lot more time on the resources below.
The guide through this arcade classic starts with a static Pong Example with HTML5 Canvas, following from which there are increasingly advanced stages of a pong game, all the way to a playable Pong game.
with this one-page introduction which looks at
setInterval, and building
The Loki "pruning" game based on the Marvel Studios TV series looks in depth at how complex visual effects can be created in steps.