Minecraft But.. The Floor Changes!

Holding the Reality Controller locks a zone around the player. Every 60 seconds, or at a configurable interval from 5 to 300 seconds, one block inside the zone is swapped for a new type without any message. The replacement follows a fixed chain, with stone turning to sand, sand to obsidian and obsidian to gold, and is otherwise drawn from a palette of more than 100 blocks that includes rotation, natural terrain, wool, concrete and ore blocks.

The shift works in true three dimensions. It affects the full cube around the player, so floors, walls, ceilings and buried blocks all take part, and the zone follows the player's position in real time as they walk. Walk far enough and the shift moves along with the player, quietly reaching through floors, walls and ceilings. Each change can be paired with portal-style particles and a low, eerie tone, and both are optional.

The mod is meant for singleplayer worlds and multiplayer servers alike. Changes are often noticed only after the fact, since a block is usually already different before anyone sees it. The mod is client and server, so both the server and every player need it. It is published for Fabric only, with one file, 1.0, for 1.21. The code is released under the MIT License and is not open source.