The problem isn't reading ability, it's the rigid structure of words that confuses them (this happens at any age range). What is or isn't allowed? Grammar rules

The problem isn't reading ability, it's the rigid structure of words that confuses them (this happens at any age range). What is or isn't allowed? Grammar rules are invisible at the end of the day and to be honest what does 'move(.left)' signify? Even after 15 years as a programmer I find this grammar confusing, is it shorthand for 'this.left'? shorthand for an enum? I'm even wondering if this grammar is even useful, if it doesn't look anything like languages in commercial use. Using icons makes a lot more sense, as they are immediately recognizable pictures that come with the expectation of no structure to learn, and it looks like from the article they just simply put one icon after another in a list.