Create a single-page app in a single HTML file with the following requirements: - Name: Fun Game - Goal: Jump over obstacles to survive as long as possible. - Features: Increasing speed, high score tracking, retry button, and funny sounds for actions and events. - The UI should be colorful, with parallax scrolling backgrounds. - The characters should look cartoonish and be fun to watch. - The game should be enjoyable for everyone.
Make it yours. Change "Name: Fun Game" and "Goal: Jump over obstacles to survive as long as possible." to your own game, and keep the look lines ("colorful, with parallax scrolling backgrounds", "cartoonish and be fun to watch") or swap in your own style.
Cartoon endless runner over parallax hills
Fun Game, a bright one-button runner: a round cartoon character jumps over block obstacles with faces as the speed climbs, over parallax hills and clouds, with sounds and a best score. One of OpenAI's GPT-5 launch examples, made from one short prompt.
“generated entirely in a single GPT-5 or GPT-5.2 prompt, without writing any code by hand”
- GPT-5
- Plain JavaScript
- One-shot
How it was made
OpenAI's README says every demo in the collection was generated in a single GPT-5 or GPT-5.2 prompt with no code written by hand. The result is one HTML file. Which coding tool ran it isn't stated.
GPT-5 · Plain JavaScript
Source and credit
GitHub · Aug 7, 2025 · 1.9k stars
Authorship not stated by the source
Published instructions: examples/fun-game.yaml in the repo, also shown on the hosted gallery
Look notesby Reference
A side-scrolling runner in bright cartoon colors: a round pink character with big eyes hops over pink block obstacles with faces, under puffy clouds and a glowing sun.
- Color
- Sky blue fading to lavender, white clouds, a pale yellow sun, layered blue hills, striped green grass, and coral-pink obstacles.
- Type
- Small rounded pills along the top for the game's name, score, best, speed, and sound.
- Framing
- 16:10, flat side view. The character stays near the left edge on the grass line while obstacles scroll in from the right; most of the frame is sky.
- Structure
- Running on open grass, obstacles of different heights arriving, jumps over a tall block and groups of small ones, and fresh runs after misses, with the score resetting and the best score kept.
