Article · 2026-08-05 · 6 moments

One-shotting a Raccoon Heist game using Claude Fable 5

Back in 2024 I tweeted screenshots of a game concept generated by GPT-3 and some concept "art" created using DALL-E. Today, on the fourth anniversary of that tweet, I decided to see if Claude Fable 5 (running in Claude Code for web) could build the entire game from the content of that tweet. It did a pretty good job of it! You can play the game here. Here's a short video demo: Your browser does not support HTML5 video. How I built this This is the August 5th, 2022 tweet: My GPT- ✦ AI generated

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HOST Simon Willison

Mechanism

Claude Code for web can be made testable during development by deploying to GitHub Pages from its working branch.

The author describes a workflow where Claude Code pushes to a branch, and by configuring GitHub Pages to deploy from that branch, each commit is live within 30 seconds for immediate preview.

transcript

Simon Willison: A frustrating thing about Claude Code for web is that it can be hard to test what it's working on while it's still working. I've been using GitHub Pages to work around that limitation, and found it to work really well. … Within about 30 seconds of each push the latest content will be visible at yourname.github.io/your-repo/.

Claim◆

Claude Fable 5 can build a fully working browser game from a single tweet's content.

The author gave Claude Fable 5 two images and a prompt derived from a 2022 tweet, and it produced a playable 3D browser game with procedural music, textures, and multiple mechanics.

transcript

Simon Willison: Today, on the fourth anniversary of that tweet, I decided to see if Claude Fable 5 (running in Claude Code for web) could build the entire game from the content of that tweet. It did a pretty good job of it!

Data◆

Claude used Playwright to smoke-test its own game, taking screenshots that caught real bugs invisible in desktop tests.

Fable ran Playwright to take screenshots at desktop and mobile widths, which revealed that the raccoon was invisible on mobile (a CSS issue masked by desktop DPR) and that the win screen's star-rating div swallowed taps.

transcript

Simon Willison: Then it built out the first basic version of the game, then decided to 'smoke-test in the pre-installed Chromium' using Playwright. This meant it could take screenshots of its own work and eyeball them. It did that for both desktop and mobile widths of the page, then noticed that the raccoon was invisible at mobile widths, so it fixed that. … Testing caught two real bugs worth mentioning: the canvas rendered at 2× size on any real phone (a cssText assignment was wiping Three.js's inline sizing — desktop DPR-1 tests masked it completely), and the win screen's star-rating div inherited the title screen's full-screen .stars CSS and silently swallowed every tap on the 'next night' button.

Prediction

Designing games that are fun remains a uniquely human trait requiring skill and experience beyond what AI agents can currently bring.

After building many games with AI, the author concludes that all have been disappointing from a gameplay perspective, and that making fun games requires human design skill that neither he nor Claude currently possesses.

transcript

Simon Willison: I've vibe coded up quite a few games now. They've all been deeply disappointing from a gameplay perspective - it turns out designing games that are fun remains a uniquely human trait, and one which requires significantly more skill and experience than either Claude or I can bring to bear.

Example

Giving Claude Fable access to an OpenAI API key lets it generate textures and title art, filling a capability gap.

The author provided an OpenAI API key, and Fable used it with gpt-image-2 to generate all game textures and the title screen art, committing them as static assets so the deployed game makes no API calls.

transcript

Simon Willison: I didn't make any technology choices. I assumed (correctly) that it would probably use Three.js based on previous experiments. Giving Claude access to an OpenAI key turns out to work really well for filling in gaps in its capabilities - in this case we needed some way to generate images to use as textures. Fable is very good at prompting image generators!

Claim

The resulting game is impressive as a starting point from a single prompt, but mediocre as a finished game.

The game is fully 3D with multiple mechanics (items, guards, dog, police cruiser, seagull), works on mobile, and has procedural audio, but is very easy to beat, boring once items are collected, and lacks any team mechanics despite having two decorative raccoon crew members.

transcript

Simon Willison: It's an impressive starting point, but it's not a good game. … As a finished game project, it's mediocre. As a starting point from a single prompt I think it's very impressive.

Highlight slides

Claude Fable 5 builds a game from a single tweet✦ from: Claude Fable 5 can build a fully working browser game from a single tweet's content.Claude Smoke-Tested Its Own Game with Playwright✦ from: Claude used Playwright to smoke-test its own game, taking screenshots that caught real bugs invisible in desktop tests.Screenshots Caught Bugs Desktop Tests Missed✦ from: Claude used Playwright to smoke-test its own game, taking screenshots that caught real bugs invisible in desktop tests.

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