Sprites on the Web

I've read all sort of resources on Javascript and never remember coming across steps() before. Also, I got a third of the way through the article before realizing the first image is right-clickable and you can see the sprite sheet right there, which was cool to see after having it explained.

If the author is reading this, I like the presentation style and formatting. However, you should know that I stopped reading once the cartoon character popped out of the left side of the screen and a speech bubble covered the text asking about a newsletter. So maybe defer that until the end or find another way?