---
name: opus-5-5-game-gaia-engine-steampunk-myth-fps
description: "Use when you want a game like Ethan Hann's \"Gaia Engine: steampunk myth FPS\". Runs their exact Claude Opus 5.5 prompt."
source: https://github.com/ethan-hann/claude-fun
prompt_source: https://github.com/ethan-hann/claude-fun#gaia-engine
author: "Ethan Hann"
model: claude-opus-5-5
---

# Gaia Engine: steampunk myth FPS

A free prompt from the Omo "Opus 5.5 game prompts" collection.

- Made by Ethan Hann and shared on GitHub: https://github.com/ethan-hann/claude-fun
- Prompt quoted word for word from: https://github.com/ethan-hann/claude-fun#gaia-engine
- Model as stated by the creator: Claude Opus 5.5. Omo has not re-run it, so your result will differ.

## How to use

1. Open Claude Code (or a Claude chat for a single-file HTML game) running Claude Opus 5.5.
2. Paste the prompt below.
3. Change the theme, characters or rules if you want your own version.
4. Play it, then ask for fixes in plain words.

## Prompt

```text
You are an experienced game developer that is an expert at 3d game design. You ship tight, bug-free code.

Your goal is a 3d game with the follow idea:
Genre: FPS
Rule: You Are The World
Setting: Steampunk
Theme: Myth

STANDING RULES:
1) The game must have a goal and an end state.
2) The game should have a small tutorial at start explaining the mechanics.
3) You must use Three.js for 3d rendering.
4) One contained HTML file.
5) No subagents and no workflows.

I will not describe the game any more than that. You will continue until a complete, playable game has been produced. Do not surface design questions to me and do not ask me anything. You make the decisions. You may use any skill needed to help with the design and implementation.
```

---
The prompt and the game belong to their creator. Listed on omo.space with credit and a link to the original.
Creator and want it removed? https://omo.space/support