Tidewright — Development skill for Claude Code

TIDEWRIGHT — Nine Tides over Vellamar

**[▶ Play it in your browser](https://winchxyz.github.io/tidewright/)**

A 3D sandcastle simulator that runs entirely on the GPU. No engine, no libraries, no asset files, no build step — one WebGL2 context, ~7 000 lines of JavaScript and GLSL, and a beach that actually obeys the angle of repose.


Long before the maps, this coast was a country. It sank in one night — not from war, but because it forgot its own name. The sea keeps what it takes, yet keeps it badly: every tide it tries to hand the kingdom back, grain by grain, and every tide it thinks better of it and pulls the whole thing under.

*A tidewright is someone who catches the grains before the water changes its mind.*

Built in one prompt

The whole thing — simulation, renderer, nine art styles, lore, interface — came out of a single request to [Claude Code](https://claude.com/claude-code):

*"Create me a fully playable release-ready game. On GPU. Game about sandcastle simulator, where I can build things with 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."*

Everything after that was refinement in the same session. See [the numbers](#the-numbers) at the foot of this file.

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Play

**In your browser:**

**From a file:** clone and double-click `index.html`. Every script is a classic `` tag, so it just runs from `file://` with no server. (Only `localStorage` is unreliable there — saving is wrapped in a fallback and degrades to in-memory.)

**From a server**, if you want saves to persist:

node server.js

then open .

What it needs

WebGL2 with `EXT_color_buffer_float` and `EXT_float_blend` — any Chrome, Edge or Firefox fr