I Built a 3D Game for My Little Cousin With AI. It's Now on the App Store.

What vibe coding can actually ship, from a non-game-developer's weekends

My little cousin loves dinosaurs more than anything. A few weekends ago I decided to make a dinosaur game just for them. I'm not a game developer. I had never built a 3D game, never touched a game engine seriously, and never submitted anything to the App Store.

Today that game, Dinomino, is free on the App Store and Google Play. This is how it happened, and what it says about what one person can now build with AI.

Here is a 35-second gameplay clip:

What Dinomino is

Dinomino is a 3D dinosaur tycoon game for kids. You hatch eggs in incubation nests, raise baby dinosaurs, and bring two of them to the Love Cloud, where they merge into a brand-new species. Shops earn you coins to expand your park, and you walk around with a big on-screen joystick that small hands can use. Progress saves automatically.

It's built with Three.js and wrapped to run as a native app on iPhone, iPad and Android.

How "vibe coding" worked in practice

I didn't write a design document. I described what I wanted in plain language and let the AI write the code. Then I played it on my phone.

The single most useful habit: screenshots. When something looked wrong, I took a screenshot and sent it back with one sentence. "The joystick covers the shop button." "This dinosaur is floating." It's far faster than explaining a bug in words.

The second habit: tiny, specific requests. "Make the egg wobble before it hatches" works. "Make hatching more fun" produces something generic.

The third: a real tester. Watching my cousin play showed me in thirty seconds what I would never have noticed. Kids don't read instructions, they tap everything, and they lose patience fast.

What the AI was great at

• Setting up 3D scenes, lighting and cameras
• Game logic: eggs, timers, merging rules, coins
• Turning a vague idea into a working first version in minutes

Where I still had to think hard

• Save and load. As features piled up, keeping old saves working needed care.
• Performance on phones once many animated dinosaurs were on screen.
• Store submission. Screenshots, privacy forms, review rules: no shortcut there.
• Taste. The AI will build anything. Deciding what should exist is still your job.

What this means

A few years ago a game like this would have needed a small team. Now the bottleneck isn't writing code, it's knowing what you want and testing it with real people.

If you'd like to see the result, Dinomino is free:

• iPhone and iPad: https://apps.apple.com/us/app/dinomino/id6809052147
• Android: https://play.google.com/store/apps/details?id=com.kodnuke.dinotycoon

I'd love to hear what you're building with AI, or any questions about the workflow.