cssDOOM
DOOM rendered entirely in CSS. Every wall, floor, barrel, and imp is a div, positioned in 3D space using CSS transforms.
cssdoom.wtf
And here is an article by the creator*:
CSS is DOOMed!
Every wall, floor, barrel, and imp is a div — DOOM rendered entirely in CSS. Using 3D transforms, CSS math functions, @property, clip-path, anchor positioning, and SVG filters to build a fully playable 3D first-person shooter in the browser without Canvas or WebGL.
nielsleenheer.com
* Madman
