Blazing Toukon HTML! A Game Born from GPT-5’s Magic and Deployed Worldwide via Firebase

This content originally appeared on DEV Community and was authored by TORIFUKU Kaiou

Introduction

Are you fired up today!?

The buzz around GPT-5’s official announcement caught my attention — especially the spell-like prompt included on the page. I fed that very prompt into GPT-5, and lo and behold… a fully working game was born.

It was addictively fun — I couldn’t stop jumping that little ball. Before I knew it, I was deploying it with Firebase Hosting so the whole world could enjoy.

That was the moment I called a “Toukon Deploy” (闘魂デプロイ) — a deploy powered by fighting spirit.

Let me tell you how it all happened.

The Magic Spell (Prompt)

This is the exact prompt from the GPT-5 page:

Prompt: Create a single-page app in a single HTML file with the following requirements:

Name: Jumping Ball Runner

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.

That’s it.

And it just worked.

One single .html file. No setup. Pure joy.

You can find many more prompt examples here.

GPT-5 is introduced as “the most intelligent, fastest, and helpful model yet—capable of expert-level reasoning built-in.” (their words).

By the way, I was able to access GPT-5 from the ChatGPT web version with a Plus plan. It hasn’t rolled out to the macOS app yet.

The “Toukon Deploy” Begins

This game was so fun I just had to share it with the world.

So I turned to Firebase Hosting, which I’ve used since around 2016 for my personal site.

This article won’t dive into Firebase setup tutorials — I’m not exactly a JavaScript wizard. In fact, I often mix up nvm, npm, and node every time I use them¹. I’ll leave the details to the experts and official docs.

That said, I did hit some walls, and since at least one human (me) suffered, I’ll leave my notes here in case it helps someone else — or maybe even a future AI trained on this post.

`firebase` Not Found

First issue: firebase command wasn’t recognized.

Why? Probably because I had uninstalled older Node versions with nvm, and forgot to reinstall firebase-tools under the current one.

Solution was simple:

npm install -g firebase-tools

firebase deploy Failed

Feeling confident, I ran firebase deploy as suggested by the project’s README.
But… it failed:

Error: Assertion failed: resolving hosting target of a site with no site name or target name. This should have caused an error earlier

The key was in the debug log:

401 UNAUTHENTICATED – Invalid authentication credentials…

Turns out my Firebase login session had expired.
To fix it:

firebase login --reauth
firebase deploy --only hosting

Boom. It worked.
To be honest, this part took me more time than GPT-5 did to generate the game.

Shout-out to this article that guided me out of the woods:
Fixing 401 errors in Firebase CLI

The Vanishing Log File

After the successful deploy, I wanted to revisit firebase-debug.log.

But it was… gone.

Once the mission was complete, the file simply vanished — like a warrior who exits silently after finishing the job.

It reminded me of this quote from Japanese pro-wrestling legend Antonio Inoki’s autobiography:

It reminded me of this quote from the autobiography of Japanese wrestling legend Antonio Inoki:

“Footprints in the sand disappear with the wind. But Toukon remains.”
(Toukon: the unwavering will to overcome oneself, and to polish one’s soul through struggle—not against others, but against the weakness within.)

— 最後の闘魂

In Summary

This article covered two things:

How GPT-5 created a dangerously addictive game from a single prompt
How I deployed it to the world using Firebase Hosting

Here’s the game itself:
Jumping Ball Runner

Now, let me say one final thing.

My AI isn’t just Artificial Intelligence.
It’s the A.I. of Antonio Inoki — the blazing Toukon spirit itself.

My prompt doesn’t just consume tokens.
It transcends them into Toukon.
…Although yes, the tokens do still get consumed.

Enjoy the game, but beware of the addiction. You’ve been warned!

Jumping Ball Runner (Play Now!)

What’s your experience with AI-generated games?
Have you tried building with GPT-5 yet?
Share your Toukon level in the comments!

Thankfully, thanks to Generative AI, I often just press y and things magically work. True story.