It's a copy of someone else doing exactly the same thing (2 layers of breakout played by moving window) but in C++ (which the author credits) both years before the following. Although the general concept of having games creatively use windows is probably much older. I assume it showed up now because of recent trend of people rediscovering that this concept works in (some) browsers and making various non breakout variations of it of it https://news.ycombinator.com/item?id=38413660