How this works: the ground is flat terraces at 5-ft steps, drawn as rectangles on the grid. Wherever two heights meet, the page works out a sloped bank between them and covers it in the same grass as the lawn; move a terrace and the bank re-forms. Rocks, bushes and trees are generated pieces pushed into the bank. This is not voxels (no blocks) and not sculpted terrain (nobody shapes the surface by hand): the only thing drawn is the flat terraces. Pawns stand on terraces and flat-topped rocks, not on the bank.
A demo only. Nothing here is in the game yet.