Wander the world.
Watch the rules run.

Eight neighbors.
Endless consequences.

Partition → update → shift

The world splits into independent 2 × 2 × 2 blocks. Inside each block, sand falls into empty cells, favoring straight drops over diagonal moves. Then the partition shifts one cell along all three axes. New neighbors carry motion through the world.

Every block type is just a different entry in that one rule. Dust and basalt fall. Water falls, then slides along a heading it carries, turning at walls, and grains sink through it. Thrown embers and spray climb along a heading, tip over, and fall. A lone meteor jumps to the opposite corner of its block, which flies it in a straight diagonal: the classic billiard-ball rule. Springs, magma, and vents fill empty cells in their own block; in the sky land they drop what they make straight down: falling water, glowing embers, and sand. Hot springs throw spray and swallow it again, and lava spouts spill embers down cliff faces. Drains and vents empty water from their block, and grain drains empty sand. Falling water takes a heading only when it lands, and embers cool only once they rest. Exposed basalt and stray drops fade away. Creatures are single blocks with rules of their own: beetles walk their heading, climb small steps, and chew basalt; fireflies drift low; fish trade places with water and never leave it; and birds fly the billiard-ball way, straight across their block until something is in it. The only outside inputs are the step number, which sets when each volcano and geyser is active, and the sky, which drops a meteor now and then.

Dust is conserved and stone stays fixed, including the slab of volcanic glass. Only a few things are drawn rather than simulated: the mirror's polished faces, the astronaut you see in them, and the natives you may come across out in the canyons: tall striders that graze and lift their heads to regard you, herds of rock crawlers that scatter, ember hoppers that go dark and pass for boulders when you come close, and gliders circling under the sky land. You can walk on every solid voxel, including fresh basalt, and wade through water. Small steps are climbed automatically; jump to clear higher ledges. These are dissipative, playful gravity rules rather than a precision physics simulation.