Trades with villagers, penned livestock, a cottage that grows while you sleep, and rain.
Wave 4 added villager trades with daily stock, carrots that need watering, penned livestock and fawns, an elder who builds a 161-block cottage over the game days, tools that wear and a bench to repair them, and rain with wind in the canopies. Hillsides became continuous slopes and the root flares became sculpted buttresses.
Villagers trade from a daily stock: wheat, bread and ingots for tools and seeds. A second crop arrived, and penned deer became livestock with fawns. The village grows on its own: the elder builds the cottage on a plot from the generator's own palette over the game days, and it keeps growing while you sleep. The 60-minute session ran with 0 faults at 239.6 frames a second, frames at 4.3 ms at the 95th percentile, world memory at a median of 20.08 MB and at most 22.77 MB, 106 saves with none failed and 79 teleports. The story test passed 52 of 52, including a full trade loop and a village that grew while the player slept, and 318 unit tests passed.
Meshing the slowest chunk in under 3 ms, an aim of this wave's geometry work, was carried forward; the next wave measured it at 5.1 to 5.6 ms on a quiet machine, still over.
This work is in every build since, including the one live on our demo host today (live rebuild 26, 17 October 2026).
Every wave closes with a play test on the build machine in the browser, at a 12-chunk view: frame rate, faults, world memory, and a scripted story test that plays the new loop end to end and reloads the world to check it came back exactly. What did not pass is written down and carried into the next wave.