Simon Willison describes a game experiment called "Tree Appreciator" created with Claude Opus 5.5 Max. The game, built in three.js, presents two algorithmically generated trees and challenges players to appreciate their differences through a spot‑the‑difference style mechanic. After three hours and seven minutes of processing, Claude produced a polished, music‑and‑animation‑rich game with achievements that feels both fun and beautiful.
Simon Willison experimented with Claude Opus 5.5 to compose computer game music, specifically aiming for a style reminiscent of the original *Secret of Monkey Island*. He designed a simple text-based format for the music and built an artifact capable of playing it, including example tracks. The results were surprisingly good, prompting questions about whether this compositional ability is a new capability emerging in recent text models.
Panache is a real‑time strategy game for mobile and browser set in France’s Belle Époque around 1900, featuring steampunk elements such as dirigibles, steam‑powered trucks, armored ships, and marching fortresses. The game was released under an Apache 2.0 license and already has a French‑language fork that reskins it to a steampunk 1900s France, adding an animated intro and French‑twisted music. The updates are mainly aesthetic, with new models and an intro video showcased on the game’s page.
Simon Willison introduces GPT‑6 Astra, a new model that offers improved attention to detail, better prompt comprehension, and the ability to generate more sophisticated outputs. The model excels at creating 3D renderings, producing detailed scenes such as gardens, shipyards, animals, cityscapes, and even Dyson spheres. Willison highlights its whimsical creativity, noting examples like a pelican wearing a red neckerchief riding a bicycle.
Simon Willison discusses a new inflection point in October 2026 for creating video games using AI, noting that Claude Opus 5.5 now reliably produces compelling 3D models, music, and especially game design. He reports having successfully "vibe coded" four enjoyable games without inspecting the code, and highlights that the real challenge is now generating novel, delightful concepts that AI alone could not conceive. The author compares Opus 5.5’s fun factor to GPT‑6 Astra, which he finds lacking in that regard.
Simon Willison demonstrates how to use Blender with coding agents on macOS by installing the full Mac application from blender.org and issuing prompts to ChatGPT Codex. He shows a step-by-step example where the agent renders a scene of a pelican riding a bicycle, then adds background flair and improves the image. The resulting image is generated via Blender's Python API.
The article describes how Jacob Sansbury’s team built a massively multiplayer game called Spawn, where players can prompt an in‑game AI agent, Savi, to modify the world—creating castles, dragons, and more. The development process is fully autonomous, with Fable‑powered agents that read errors, bug reports, and metrics, then directly modify live code and ship changes to production every hour. The system treats any hour without a ship as a severe incident, enabling rapid rollbacks and continuous deployment at a scale that costs over $3 million in AI tokens monthly.
Battle Drones is a browser‑based, Command & Conquer‑style real‑time strategy game that evolved through 12 major iterations, adding 3D models, varied terrain, random map generation, and both local and online multiplayer via audio synchronization. The game features nine buildings, seven ground vehicles, six aerial vehicles, and three infantry units, with fog of war, area‑effect weapons, and multiple play modes such as skirmish and last‑stand. The project showcases how AI‑assisted coding (primarily Claude) can accelerate game development and introduce innovative multiplayer mechanics using sound.
Simon Willison created a .blend URL Viewer tool that lets users view a Blender model of a Fabergé egg themed after the TV show Pluribus directly in their browser. He generated the egg image using ChatGPT Images 2.5, then fed it to GPT‑6 Astra with a custom Blender skill to produce several .blend files. The viewer, built with JavaScript, is now part of his tools collection for easy access to the resulting 3D model.
Simon Willison presented a closing keynote at the WeAreDevelopers World Congress North America, where he showcased a pixel‑art animation of kakapo parrots celebrating a record‑breaking breeding season in 2026. He used Claude Opus 5.5 to generate the animation from Google‑searched kakapo photos, then employed Claude Code with Playwright to record a 15‑second video of the animated HTML5 canvas, which he embedded in his Keynote slide.
Claude Cowork and the standard chat interface are merging into a single Claude experience, allowing users to hand over tasks or ask quick questions that the system will continue to handle even after the laptop is closed. The rollout will begin with Pro and Max plan users across web, desktop, and mobile, and will extend to new users on these plans over the coming weeks. This integration suggests Claude is evolving into a general agent, simplifying the distinction between Cowork and regular Claude usage.
The article discusses Anthropic’s Claude Fable 5.1 release, highlighting its claimed improvements in coding, knowledge work, and problem‑solving, particularly a 52.6% score on the new Terminal‑Bench‑Science 0.1 benchmark. The author examines the model’s performance on the pelican benchmark, noting that Fable 5.1’s five reasoning levels (low, medium, high, xhigh, max) sometimes skip reasoning entirely for certain prompts, as evidenced by token counts and cost metrics. The piece provides detailed transcript data for each reasoning level when generating an SVG of a pelican riding a bicycle.
Release: llm-gemini 0. 33 It's been a while since the last llm-gemini release.