What people built with Claude Opus 5.5, Sonnet 5.5 and Haiku 5.5

A physicist wrote that Opus 5.5 did a quantum gravity calculation (a theory that tries to explain gravity with quantum mechanics) in 10 hours. The physicist had spent a year on about 500 pages of hand work for a doctoral thesis. Opus 5.5 also wrote the paper and a GitHub repository. The result is in the GitHub repository linked in the post.

#210A year of quantum gravity hand calculation, redone in 10 hours with a paper

#212A huge world built from scratch in Unreal Engine

#217A top-down RPG demo with NPC routines, weather and a day-night cycle

#193A fantasy RPG of crab robots, built with two sons

#196An ancient Greek world built with code only and 0 external files

#195A tool that cuts monster motion transfer from 4 days to minutes

#202A squad combat game in its 20th day, with no code read

#213Voltane, a split-screen RC car game built in under a month

#197A 25-minute animation made in 15 hours with code and no video AI

#194A snowy plaza game prototype built in 30 minutes

#216An Unreal space exploration game with C++ and shaders both written by Opus 5.5

#220A retro-futuristic RTS and FPS hybrid built over a few days

#203A real-time WebGPU ocean in one 61KB HTML file, with no engine

#214A game with faster development from Opus 5.5 animation

#201A C++ game engine that turns the whole Earth into an open world

#198A game merge test that puts Minecraft inside a GTA 5 city

#18A cleanup screen that scanned a Mac disk and found 97GB of junk

#208An improved Clawd animation made with Opus 5.5 Ultracode

#199Doom running on a Casio F-91W wristwatch screen

#200A corporate crisis explainer video made with Opus 5.5

#204An ink-wash video on the 2008 stock crash, made in 2 hours

#205An animated process infographic from a few lines of text

#192A typewriter video with lamp light and keyboard drawn only in code

#2094 missed performance bugs fixed in a 3-hour run, speeding up an app

#207An iPhone 4S video edited from raw footage, with a cute ending

#7A Little Prince game with a 3D scene for each star, made in 16 days

#188A US cross-country route from 5,285 km of real roads at 10 m spacing

#187A map video of a fictional Malaysia and Indonesia conflict

#190A Minecraft minecart that lays its own rails across oceans and lava lakes

#186A Metro 2033 Redux mod with 7 new weapons, made with Opus 5.5

#189An hour-by-hour simulation of Singapore taking Batam

#183A game mod built in under 2 hours that doubles FPS

#206An HTC HD2 QEMU emulator built with zero human review

#17A full 3D Airbnb from a few photos and a floor plan

#177An Age of Empires-style strategy game from vibe coding alone

#182A Godot city builder with an 8-step building pipeline replaced

#191A macOS mouse button settings app from a single prompt in 5 minutes

#181A Japanese study shrine game made with Opus 5.5 except the music

#173Multiplayer Attack on Titan Minecraft in 1 hour for under $25

#179A moody night laundromat built in Blender with prompts alone

#175An A380 SVG animation with 600+ parts, drawn over 48 hours

#168A first-person Valorant Breach game on a League of Legends map

#171Minecraft in Red Dead Redemption 2 with Arthur Morgan stacking blocks

#185A video Opus 5.5 made on whether it is conscious

#174A hex-tile island-building game from dozens of prompts

#178A Street Fighter 2-style fighting game with AI company CEOs

#184A 7-step explainer of how Claude answers, made entirely in the browser

#169A realistic betta fish on a Mac wallpaper

#176A holographic 3D card effect from the low-cost Haiku 5.5

#180A glass box world: squeeze a cloud for rain, shake it for lightning

#172A video of a Nether portal and a Creeper in the middle of a GTA 5 city

#170A 3D Terraria-style game with 3,300 items added in 8 days

#3Industrial software that runs a warehouse like a strategy game

#167An HD-2D-style 3D pixel-art game made with Three.js

#164A pixel game from engine to combat in three one-shot prompts

#162A skill that makes a web book with a quiz from a PDF alone

#163A 3D company island where building height is market capitalization

#161An endless valley flight game from a single prompt

#160A no-account life-log app made in 8 days by looking only at an iPhone

#165Motion graphics received at once from the next app version code only

#159A 24-hour pixel news broadcast, PNN, made in one week

#158A pixel-creature workshop about 95% made from a one-shot prompt

#152An AI pop star music video from two reference images and a one-shot

#151A chess game drawn to look like doodles on paper

#157A game received in 3 hours from a 20-year developer's design

#146A T-shirt clothes rack portfolio site from three prompts

#153A Mona Lisa in SVG from memory alone, no reference, over 15 minutes

#155A Blender SpongeBob side by side with GPT-6.1 Sol on the same test

#2A smiling sun built block by block, with no commands

#9A smart home dashboard on one HTML page with no framework

#143A browser Fallout game built in code, with no images or sound files

#148An Opus 5.5 video with both picture and sound made only in code

#145A Fortnite-style game from one shot for under $20

#149An invoice app, landing page and promo video from a few prompts

#166A Roblox game from design to thumbnail with a single prompt

#14A multiplayer stickman game that destroys websites, made in a weekend

#147Pokémon Red rebuilt in about 25,000 lines of code, with no image files

#144A space exploration game with 80 planets from a single prompt

#156A camera carousel shot by a gun and falling, from a one-shot prompt

#154A hologram card with depth from a 3D sword on PNG image layers

#12A personal budget dashboard, SharkFin, on 35% of the weekly limit

#15A 3D city game that runs in the browser, on the third try

#150A 150-bun pixel game with art, music and trailer made by the model

#138An old-school MMO RPG built solo in 36 hours on $2,175 of tokens

#139A Minecraft mod trailer made from a single mod file

#125A 3D pixel game from about 2.5 five-hour sessions on a $20/month plan

#6A 15-second motion designer showreel from a one-shot prompt

#13A shape-morphing UI motion video made only in code, no After Effects

#128An 8-minute 3Blue1Brown-style explainer made from a single paper

#127A Splatoon-style 3D ink shooter you can play by opening a link

#142A 3D chess roguelite written entirely in code from 4 reference images

#140A 3D energy drink website that tests itself and fixes its own errors

#16A verified life-size microduck: 1,113 real LEGO parts, zero collisions

#136A life-purpose collage video from a one-shot prompt and $3.21

#135A text-art video from a single request to show what's in its mind

#130A collage-style app explainer, made solo in under 2 hours for about $4

#129A 3D island town built in about 8 hours with $1,874.40 worth of tokens

#132An SNES-style AI battle video in pure code, with no art or music files

#124A 40-minute Three.js road-to-the-castle game, music and art included

#126A paper-cutout-style game trailer starring BOB the snail

#141A 3D driving game with music notes, radio and roads that defy gravity

#108A Teemo intro from a one-shot prompt with official Riot stats it found

#8A 3D lens lab from a one-shot prompt in 1 hour 26 minutes for $25.66

#81A hand-drawn style space animation of swirling planets and orbits

#95A pixel art animation of a neural network learning handwritten digits

#1345 games from one-shot prompts, with 3D models built in Blender

#13710-minute, code-only pixel art of a floating island on a rainy night

#131A 3D boat you steer through Japan as weather and time of day change

With one sentence per game, Opus 5.5 in Claude Code made a game about a pelican riding a bicycle, a first-person shooter (FPS) that recreates CrossFire's transport ship map, and a QQ Speed-style racing game. The model did everything alone in one conversation, from research to writing code, testing and deploying to Cloudflare Pages, and no human changed a single line of code.

#58Three 3D web games from one sentence each, deployed untouched

#82A paper-plane letter story with every frame drawn in JavaScript

#57Browser Minecraft with sunset light reflected on the waves

#133A 3D game that turns the trolley problem into smashing combo action

#83No video model, only code brushstrokes: the life of Opus 5.5

#85A short film built from scratch by 4 agents in 1 hour 30 minutes

#60A gacha game where you pull barbecue grills instead of girlfriends

#42A Minecraft-style block world with realistic light and clouds

#41A pelican cycling in a Three.js city, built to celebrate the launch

#86One prompt, 4% of the weekly limit: a 1-minute office horror video

#88Travel photos in JavaScript alone: an acrylic New Zealand picture book

#91A raindrop story video it made when asked about its new abilities

#87No image files, only code: a self-portrait facing hard problems

#89An oil-painted seaside animation with every frame drawn in JavaScript

#103A cartoon video editor animation drawn only in code, no video AI

#96A hand-drawn-style music video Opus 5.5 made to fit a song

#123A macOS music app in about 35 minutes and a 63-minute iOS word list

#90A Shotbase launch video from one shot in under 20 minutes

#92A hand-drawn history of Claude from one skill and plain JavaScript

#94Theme left to the model: a 70-second JavaScript video of birds at dusk

#65A no-install NBA 2K-style 3D basketball game in the browser

#70A Pune auto-rickshaw 3D game from a single prompt, no code (India)

#61A from-scratch Spider-Man-style game, from 3D models to animation

#101A running pixel horse drawn in code in one HTML file, no image files

#59Minecraft that runs right in the browser with no install

#93In under 5 minutes, a pixel animation of a rainbow road in space

#99A short film test scene from 46,000 characters of code, no video model

#69Platformer and rhythm games vs. GPT-6 Sol from the same one-page brief

#97A full video about making a voice app, from a one-shot prompt

#66A pressure washer game in Rust and WebGPU that also runs on phones

#98A claymation of the motor protein kinesin from a single prompt

#63A 3D dogsled race under the aurora, set beside GPT-6 Sol's version

#105A one-shot, code-only animation of Claude solving a hard problem

#43Same prompt as GPT-6 Sol, side by side: a 3D planet base scene

#44A 3D monster rigged with jump and bite moves in 40 minutes

#119The coding agent app T3 Code, moved whole into Minecraft

#102An SVG New York skyline in one HTML file from a one-shot prompt

#120A living sketchbook that draws what you type and moves by keyboard

#62A Minecraft clone with water physics, playable right in the chat

#64A doodle first-person shooter with a boss fight from a one-shot prompt

#121A map of the Mongol conquests, 1206 to 1294, from a one-shot prompt

#100An Opus 5.5 launch video in JS code alone, with no music or images

#107A sand art animation with voice and sound effects from one prompt

#122One-click blog explainers with source citations for each arXiv paper

#68A Fortnite-style battle royale game from a one-shot prompt

#67A pixel game map animated down to fountain ripples and cave bat eyes

#106A 22-second chalkboard animation with music the model made itself

#104An animated history of GPT models in plain JavaScript alone

#4A single prompt, 12% of the usage limit: Opus 5.5's own launch video

#10A one-song music video drawn in code, with no scene directions

#11A printmaking-style train journey drawn only in JavaScript, no images

#19A 9.5-hour Rust port of HAProxy passing nearly all its tests

#77An investment app promo video made start to finish in 10 minutes

#72The code-only animated story Anthropic showcased first

#118The best visual design of any model tried

#2216 code fixes that caught a concurrency bug from a few short requests

#71Old-master-style paintings from 7,500 lines of code, no image AI

#114A landing page with motion, built in minutes from one reference site

#46A multiplayer lawnmower game viewers joined as soon as it was built

#110100 HTML pages from three rules, with zero broken files

#47A Roblox brawler from a one-shot prompt, using only built-in tools

#45An Antikythera game in one HTML file with no images or audio

#79A site that turns any photo into a one-line drawing and drawing video

#21A new algorithm beyond a paper's limit, found and proved in 15 hours

#84An SVG animation of two AI logos facing off, from a one-shot prompt

#55An explorable tiny planet made in 14 minutes for $2.54 in API fees

#113A one-shot 28-minute redesign of an app earning $10K a month

#26A Blender claymation from a one-shot prompt

#75A living pixel art wizard made only with code, no image files

#48A Dark Souls-style action game built in Unreal Engine

#32San Francisco in Unreal Engine, down to moving people, pets and cars

#38A moving 3D 'pelican on a bicycle' in 19 minutes 16 seconds

#33A 3D code animation that grows from one line into a finished house

#29A Shinkansen with 5,112 parts and 430 seats, each built separately

#28A whole San Francisco street before the 1906 quake, in one shot

#27The exact second of the 1968 Earthrise photo, found from one image

#73An animation made in 18 minutes 31 seconds from a one-shot prompt

#74A short film with story, art and music by the model and no human code

#117A PS5 controller a step above GPT-6 Sol on the same prompt

#111The Claude Code screen redesigned as a napkin written in pen

#112An app design stuck for a week on another model, solved in hours

#37A self-portrait of Opus 5.5 built from voxel blocks

#49300+ playable guitars in a shop that turns into a brawler when loud

#35A hand-drawn catapult that fixed itself after a miss and hit 7 of 10

#109A 2,874-part block model manual from just a photo or description

#30A walkable 3D house from one photo and a floor plan

#78Change one number, get a new picture every time: a drawing program

#51A Mario Kart-style racer built by 5 agents from a single prompt

#40A 334-line SVG Xbox controller from a one-shot prompt

#36A $3.40 volcanic island with sea life, a mammoth and an aurora

#31A 3D anatomical hand that shows pain causes when you point by webcam

#24A single prompt, about 1 hour 30 minutes alone: a city-building game

#2350 agents for 2 hours 27 minutes on just 18% of the usage limit

#50An endless 3D world from one instruction, with self-set goals

#56Geometry Wars from a request for just 'a fun game'

#34A one-shot cat with every strand of fur moving on the GPU

#115Gyeongbokgung simulators built by three models, compared (Korea)

#80One prompt, three AIs, and a horror short in about 2 hours 30 minutes

#76A one-shot Replit launch video made in under 15 minutes

#39A pachinko machine from a single image (Japan)

#54A Pokémon opening from an unpolished one-line prompt and $5.47

A DOOM clone that runs in the browser, built together with an autoplay AI that beats the game on its own. The autoplay won 8 of 8 games with an average hit rate of 93.4%.

#52A DOOM clone with a self-playing AI that won 8 of 8 games

#25Half the prior model's cost, 63 minutes: a merger analysis in Excel

Opus 5.5, Fable 5.1 and GPT-6 Astra were each asked to build a flight simulator, a Minecraft-style voxel game and a real-time strategy game in a single attempt, and the results were posted side by side. For Opus 5.5, each game took 46 to 48 minutes and cost $11 to $14.

#533 games in one try each, from a flight simulator to a strategy game

A web service for managing shipping risk was built from 2 prompts in 18 minutes 16 seconds. The files the model wrote were deployed as they were, without a single line changed.

#1162 prompts, 18 minutes 16 seconds: an untouched shipping service

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This is a collection of cases for Claude Opus 5.5, Sonnet 5.5, and Haiku 5.5. It gathers the things people made with these models, together with the original posts. So far, there are 245 cases across all models combined.