Comment by felineflock

Please tell me if I understood it correctly:

It implements voxels via <input type="radio" />.

Each of the faces of each voxel is configured via <label>s, one for each face having a different CSS class.

There is a voxel for each type of block (dirt, grass, stone, etc) and only one is activated at a time.

The <input>s are arranged in a 9x9 grid 10 blocks tall times the number of different types of blocks (about 6500 total).

All that is enclosed with <div>s with CSS classes that respond to the camera navigation (look up/down, move up/down, forward/back, clockwise/counter)

That is brilliant!