What is stone-age?

Stone age is a simple sandbox game described by its author as a modification of Minecraft's very earliest pre-classic version, sometimes called the cave game era of Minecraft's development. The README is short and does not go into detail about what gameplay changes the mod makes, so beyond calling it a sandbox game in the cave game style, there is not much more to say about its actual features or mechanics. What the README does explain clearly is how to install and run it. You start by downloading any Minecraft launcher, then installing a specific old Minecraft pre-classic build known as rd-161348 through that launcher. Once that version exists in your Minecraft directory, you replace its jar file with the stone-age jar file provided by this project. If the game does not start correctly after that swap, the instructions suggest renaming the new file so it matches the original rd-161348 filename exactly. After that, you open your launcher, run the rd-161348 entry as usual, and the modified game should start. Because the README does not list a license, a technology stack, or any description of what has actually changed compared to the original pre-classic build, this project reads as a very early, minimal release rather than a polished mod. Anyone interested in trying it would need to already be comfortable installing and swapping files inside a Minecraft launcher's directory structure, since the instructions assume that familiarity rather than explaining it step by step for a complete beginner. Overall, this is a small personal project built on top of an extremely old, historical build of Minecraft, and the available information about it is limited to the installation steps shown above.