? Of how little javascript you need to get a whole bunch of things done. In this game, you could efficiently generate several different objects of various animations doing different sorts of stuff simply by putting in the least of javascript. It is less resource intensive and more natural to the browser because it leverages things it expects.

Several years ago, this game would be very resource heavy and use lots of JS, but as more common uses of JS are merged into CSS, JS is less and less relied on.