Interesting concept!

There are some random green and blue lines between the "pixels" on my default zoom level, which are removed if I zoom to 110%, and vary across other zoom levels. Using the latest Firefox on windows. It seems to be caused by the shadows, which is an interesting way of doing the pixels but unfortunately ruins the image in my case.

Somewhat similar is acbf: https://launchpad.net/acbf

Intriguing concept, but the HTML output of the pixel-world-editor tool doesn't seem great (tons of absolutely positioned divs). In present day world it would be better to use svg.