Try It Yourself

About
Codex Arcade

by @AndrewMayne

Codex is a product of OpenAI. This site is not affiliated with or endorsed by OpenAI. The idea is simple: ask Codex or ChatGPT to make a real browser game small enough to survive inside a URL and eventually fit inside a scannable QR code.

If you want to try the challenge yourself, copy the prompt on this page and paste it into ChatGPT. It explains the size budget, the single-file rule, and the kinds of tradeoffs needed to keep the whole game self-contained.

Copy-Paste Prompt

Make me a tiny, self-contained browser game for the Codex Arcade challenge.

Requirements:
- The final playable game should target a budget of 2,048 characters or less for the main game payload.
- No external assets, libraries, fonts, images, audio files, imports, or network requests.
- Everything must be generated in code: gameplay, graphics, sound, UI, and effects.
- Output must be a single HTML file or a single payload that can be embedded in a URL or QR code.
- Design for a mobile browser first, using a 9:16 layout that feels right on a phone like an iPhone.
- It must run in modern desktop and mobile browsers.
- Controls should be playable on a phone: tap, swipe, hold, or very simple touch targets.
- Prioritize immediate playability, bold visual identity, and clever size-saving tricks.
- Include restart behavior and a visible score or win/lose state if the concept supports it.

When you answer:
1. Start with a one-paragraph concept.
2. Return the final game as a single code block.
3. Report the character count of the main payload.
4. Briefly explain the tricks used to stay under budget.
5. If the game is over budget, aggressively compress and revise it until it is as close as possible to 2,048 characters.

What The Prompt Does

The prompt forces the model to think like a cartridge engineer: tiny budget, no external dependencies, no hidden assets, and no room for waste.

That constraint is the whole point. If the game can fit in the payload, then the graphics, sound, rules, and interaction all travel together inside the same tiny package.