Have you considered destructability of surfaces? Or, even better, subsurfaces? Dirt, which can be swep, showing with a level of rock below. Breakable wood.
I'm very much longing for game graphics being not movie-like. I want to feel inside a game, which has its internal logic and aesthetics, but which is not trying to copy the real world to the very minute detail. The movie-like quality breaks down due to various limitations, and we end up in the uncanny valley, where the world looks real but feels like a puppet show.
What made Doom great was not only its gameplay and art, but also its kinda realistic but not realistic light and animation. What made Monument Valley great was exactly the departure from the real-life geometry The in-your-face pixelization / voxelization of Minecraft not only did not repel the kids who never saw 8-bit games, but became iconic.
What sets out the voxel displacement rendering for me is the departure from flat and glossy low-poly surfaces and edges (which the author pays special attention to). Real-world textures are rarely glossy, and edges are rarely sharp. But modeling it the way it's done in some modern games is apparently crazy expensive and requires colossal graphical assets, such that are out of reach of a typical modder. The author's approach achieves the feeling of a nice palpable texture with low-poly geometry and low-res textures; it's very promising.
Voxel means "volume element", like a pixel means "picture element". A "pixel" in a height map is not an element of a picture but an element of a volume, so, a voxel.
