You have a good point with HTML5 being different from JavaScript. It is, and not enough people understand it. Javascript is a friendly soulmate to HTML5. The majority of the game is just parts of the game engine, but there are a few features make HTML5 a more accurate descriptor than pure JS:
- CSS3 transitions - especially within the editor (also not technically HTML5)
-
<audio>element - which is actually HTML5 -
<canvas>element (most importantly) - what made it all possible. The first builds of the game just used<div>s for everything, which was crappy for performance and elegance. Now that it uses HTML5’s canvas, it runs way faster. Most elements are generated with the createElement() function.
tl;dr: There’s HTML5 there
