I created a 3D lunar rover survey game with Opus 5.

This is a 3D lunar rover survey game that runs in a browser tab. No engine, no build step, no dependencies to install, no asset files. One WebGL2 context, a vendored copy of three.js, \~6,300 lines of JavaScript, and regolith that keeps every rut you cut into it, because the wheels and the shader read the same height field. **The whole thing:** physics, renderer, terrain, lore, sound design, interface. 95% came out of a single prompt to Claude Code (Opus 5 on Ultracode) **Prompt was:** "Create me a fully playable release-ready game. On GPU. Game about moon discovery with rover with gravity, moon sand and etc.. I need it in 3D and not a voxel game. Make it with maximum effort, show me best what you can create. Use all your power, knowledge and make best graphics and best game design. Surprise me with graphics, lore and everything." It's a fully playable HTML game with two modes: a five-mission campaign and free survey. Also works on mobile. Twelve codex entries, nine sample…