# Pac-Man from one prompt, 36 ways

> PacBench, a gallery of 36 playable Pac-Man games, each made by a different model and harness from the same one-line prompt and scored on controls, ghosts, maze, and sound, with time, tokens, and cost per run. Opus 5.5 in Claude Code tops it at 99.

- Kind: Game
- Live game: https://jonclegg.github.io/pacman-bakeoff/
- Page: https://meetreference.com/v/pac-man-from-one-prompt-36-ways/
- Ready-to-use agent handoff: https://meetreference.com/v/pac-man-from-one-prompt-36-ways/agent.txt
- Exact prompt as plain text: https://meetreference.com/v/pac-man-from-one-prompt-36-ways/prompt.txt
- Authorship: Not stated
- Made with: Claude Code, Codex, Cursor, Antigravity, Grok Build
- Model: Claude Opus 5.5, Claude Fable 5.1, Claude Sonnet 5.5, Grok 4.7, GPT-6.1 Sol, GPT-6 Astra, Gemini 3.8 Flash, Kimi K3
- Built with: Plain JavaScript
- Style: Games; pac-man, arcade, retro, model comparison, single html file, benchmark
- Shared by jonclegg in GitHub, Sep 28, 2026: https://jonclegg.github.io/pacman-bakeoff/
- Prompt fidelity: Verbatim. This is the complete prompt exactly as the creator published it.

## Before you start

Guidance from Reference, separate from the creator's instructions.

1. Read the reference and inspect the project, installed libraries, and available agent skills before writing code. Reuse suitable tools already present.
2. Prefer the creator-reported libraries and skills when they fit the task. Explain what useful additions help with, and install missing project dependencies or relevant skills from official sources when the environment and the user's existing permissions allow it. Respect the project's package manager and setup rules; do not ask again for routine setup already authorized.
3. Distinguish tools used by the creator from your own recommendations. A listed tool is not automatically required, and an empty tools or requirements list means the setup is unknown, not that nothing is needed.
4. Ask concise questions when missing inputs or choices materially affect the result: paid services, credentials, the user's assets, or a different production approach. Use existing answers and permissions; continue independent work while waiting.
5. If a useful library, skill, or service cannot be installed or used, explain an available alternative and its expected effect on quality, features, or effort. Get the user's choice before a material compromise; otherwise state the fallback and continue. Never silently simplify the result or claim to have used a tool you did not use.

## Recreating this game

These are the creator's published instructions, unedited.

To adapt it: Swap "Pac-Man" for another arcade game, or start from the longer bench/prompts/pacman.md, which spells out the maze, four ghost behaviors, and the rules that keep a run fair (one file, no web, work alone).

## Prompt

```text
Create a Pac-Man game in a single html page
```

## What it looks like

Written by Reference from the recording frames, not by the creator.

Reference's recording of the top-scoring game, Opus 5.5's: an arcade-style Pac-Man with a ghost roll-call attract screen, a READY! start, and a run around the blue maze that ends with Pinky catching Pac-Man.

- Color: Black background, royal-blue double-line maze walls, peach pellets and power pellets, a yellow Pac-Man, and red, pink, cyan, and orange ghosts.
- Type: Blocky white arcade type for 1UP and HIGH SCORE, a yellow PAC-MAN title and ghost names in their own colors on the attract screen (-SHADOW "BLINKY", -SPEEDY "PINKY"), cyan PLAYER ONE and yellow READY! in the maze, and a grey key hint line (ARROWS/WASD MOVE, P PAUSE, M MUTE).
- Framing: A near-square 10:11 frame filled by the maze, with the score along the top, spare lives in the bottom left, and a cherry in the bottom right.
- Structure: The attract screen with the four ghosts and point values, PLAYER ONE and READY!, Pac-Man eating along the lower corridors as Blinky and Pinky leave the ghost house, the score climbing to 240, Pinky catching Pac-Man by the left tunnel, the maze emptied during the death, and a fresh start with one fewer life.

Storyboard, nine frames spread across the recording: https://meetreference.com/media/pac-man-from-one-prompt-36-ways/storyboard.webp

- Frame 1 at 1.2s: https://meetreference.com/media/pac-man-from-one-prompt-36-ways/f1.webp
- Frame 2 at 3.6s: https://meetreference.com/media/pac-man-from-one-prompt-36-ways/f2.webp
- Frame 3 at 6.1s: https://meetreference.com/media/pac-man-from-one-prompt-36-ways/f3.webp
- Frame 4 at 8.5s: https://meetreference.com/media/pac-man-from-one-prompt-36-ways/f4.webp
- Frame 5 at 10.9s: https://meetreference.com/media/pac-man-from-one-prompt-36-ways/f5.webp
- Frame 6 at 13.3s: https://meetreference.com/media/pac-man-from-one-prompt-36-ways/f6.webp
- Frame 7 at 15.7s: https://meetreference.com/media/pac-man-from-one-prompt-36-ways/f7.webp
- Frame 8 at 18.2s: https://meetreference.com/media/pac-man-from-one-prompt-36-ways/f8.webp
- Frame 9 at 20.6s: https://meetreference.com/media/pac-man-from-one-prompt-36-ways/f9.webp

## How it was made, per the creator

- One-shot: yes, a single prompt with no follow-ups
- Agent time: 9.3 minutes for the Opus 5.5 run in Claude Code; every card lists its own
- Reported spend: $1.99 for the Opus 5.5 run in Claude Code; every card lists its own time, tokens, and cost.
- Notes: Each model and harness gets one shot, with no follow-up prompts or fixes. The scores, out of 100 for controls, ghosts, getting stuck, maze, and sound, come from Opus 5.5's re-test of the live games on 2026-09-28: a 90-second automated play test plus a source and maze audit. The early runs, including the top-scoring Opus 5.5 game, used this one-line prompt. Newer runs added through the repo's runner since 2026-09-30 use the longer bench/prompts/pacman.md (linked below), and their cards say so. The recording here is the Opus 5.5 game being played.

> Models and harnesses recreate Pac-Man from one short prompt.
> (jonclegg)

## Links

- Play game: https://jonclegg.github.io/pacman-bakeoff/
- Original post: https://jonclegg.github.io/pacman-bakeoff/
- Show HN post (80 points): https://news.ycombinator.com/item?id=49885493
- The Opus 5.5 game, scored 99: https://jonclegg.github.io/pacman-bakeoff/entries/claude-opus-5-5.html
- Longer prompt newer runs use (bench/prompts/pacman.md): https://github.com/jonclegg/pacman-bakeoff/blob/main/bench/prompts/pacman.md
- Code and run data on GitHub: https://github.com/jonclegg/pacman-bakeoff