My 9 year old and her friend wrote (kinda) a game concept over the holidays. Last week we turned it into a playable game.
They wrote this in a notebook: "Once upon a time there was a little slice of watermelon who lived in a very happy town. He met a lemon who said, there's an army of germs coming! I suggest you go to the market that sells weapons, it's not very far."
That's the whole design doc. It's called Le Royaume des Pépins. A fruit kingdom gets invaded by microbes, you play the watermelon, you purify the place and take down the evil germs that wants to destroy the kingdom. Love how kids think out of the box.
They wrote the story and drew every character. I did the parts that needed a keyboard.
How it went
We used their notebook page as the actual spec and typed it in close to verbatim instead of me rewriting it into proper design language first. That mattered more than I expected.
Their drawings drove the art direction rather than the other way around, so the characters look like theirs and not like generic AI fruit.
The core verb came from asking her what the watermelon actually does. She said purify. So that's the verb, and everything else got built around it.
Biggest thing I learned: a 9 year old iterating live beats prompt engineering. She'd play for thirty seconds and say "the germs are too slow." That is a better bug report than most I've received from adults.
Disclosure, it's built with Sandscape, which is my own tool but we use Claude and bunch of other tools like Meshy and ElevenLab.
And it's actually pretty fun to play https://sandscape.app/play?g=pDdi6wlB
Happy to answer anything about the process.