One afternoon, 450 million tokens, and a 3D action game running in 30MB of HTML

A 30MB HTML file opens into a playable 3D action game called 'Mist-Locked Mountain Gate'. Author: Guizang. It took one afternoon to make and consumed 450 million tokens.

First, the result:

Playable demo URL: https://op7418.github.io/guizang-game-skill/

The browser needs to support WebGL 2.

The models, scenes, action design, and optimization were all done by Fable 5.2. Guizang said in the tweet that the original assets totaled more than 100MB and were finally compressed to 30MB, with little loss in quality. Beyond compression, it also generated concept art, made 3D models, and added action rigging by itself, using Tripo and Jimeng CLI.

There is one detail that needs correcting. The original tweet said 4.5 billion tokens; Guizang later said in a reply that it was a typo from voice input and the actual number is 450 million tokens. This number affects cost estimates; you can't multiply based on 4.5 billion.

Guizang later added that this wasn't completed in one click. There were many rounds of changes in between, and it also referenced others' experience using AI to make games, and was finally distilled into a skill. This skill first clarifies the requirements, then researches available tools, and after that pushes forward the visuals, checks, and verifies. Combat techniques for action games, hit feedback, and optimization methods are also written into it. There is also a list of common pitfalls, one of which is key: how to compress a very large size down very small without affecting gameplay.

Skill URL: https://github.com/op7418/guizang-game-skill

There is also a demo of the optimization process:

After trying it, a user named adson_LCat said this result is a landslide lead. Another user, Beyond the Obvious, asked more practical questions: Maxing out scene detail doesn't mean the gameplay automatically works. Whether levels become repetitive, whether the control rhythm holds up, whether playtest feedback can feed back into the production process—these are harder than simply getting it to run. This judgment is worth keeping.

Some people also calculated the cost. 450 million tokens is a substantial amount. A user named Guanlan estimated based on Fable 5.2's API pricing: input is $8 per million tokens and output is $40 per million tokens. Even if almost all of it were input, it would still cost more than $3,000. Whether the actual run used the API or subscription quota, the author didn't specify, so you can't directly apply the calculation.

The most intuitive change for ordinary users is that there's no need to install an engine—just open it in a browser and play. The barrier for developers has also dropped a notch. What really creates the gap is still requirement breakdown, tool invocation, quality checks, and repeated revisions.

Chen Chen from the Bay Area compiled a list of Fable 5.2 browser games, covering shooters, racing, simulation, RPG, puzzle, and mini-games. A few representatives:

• Saltline: https://claude.ai/artifact/BGY1SztrAYcJQHSsnHHGmp
• Dead Headway: https://dead-headway.vercel.app/
• Hogwarts Royale: https://www.spawn.co/@mattshumer/hogwarts-royale
• 3D Kart Racing: https://turbo-tails.vercel.app/

Original tweet: https://x.com/op7418/status/2120694045299327187