Kristallsaal is a walk-through jewellery hall that runs entirely in the browser: six vitrines of cut-crystal pieces under museum lighting, a mirror-polished floor, and light that actually splits into colour inside the stones. There is no engine download and no build pipeline — one HTML file, one JavaScript module and Three.js, served as static files. It exists to answer a client question with a demo instead of a slide: what does "3D product presentation on the web" feel like at the high end?
fantasy.grn.dk is コトバモン KotobaMon — a 3D monster-catching game that runs in an ordinary browser tab, where every monster is a Japanese word. ヒバナ hibana is a spark, コダマ kodama is a tree spirit, and catching one is how the word gets learned. It has a procedurally generated island with five biomes, twelve species, turn-based battles with a type chart, and full Japanese voice-over subtitled in Japanese, romaji and English at the same time. There is no download, no account, no build step and no backend: the whole game is 2,821 lines of vanilla JavaScript plus a vendored copy of Three.js, served as static files.
A look at fantasy.grn.dk, a browser-based 3D game that teaches Japanese with no build step, procedural art and self-hosted AI voice, and what its constraints show about shipping interactive products fast and cheap.