# One prompt, one forest

*2026-10-04*

> Rừng Trong Kính (Forest in Glass): a 3D terrarium to look after, with a Pomodoro mode. The first playable version came from one prompt.

I don't usually believe one prompt can build anything worth keeping. Rừng Trong Kính changed my mind: one prompt, one photo of a real terrarium, and 23.5 minutes later a playable 3D game. Glass tank, LED lamp, moss, ferns, and seven days to keep it all alive.

Every prompt after that went to new directions, not to making it run: glass doors that open, levels and a shop, the thumbs-up poster from my office, then a Pomodoro mode. The tank holds still while you focus and waits for you on breaks.

The first prompt built the base. Everything added after is just a little jam on the cake.

## The first prompt

The first prompt, word for word (I only swapped the photo path). It is in Vietnamese, the way I typed it: “Make me a 3D terrarium care simulation game, modelled on the attached terrarium.” It came with a photo of a real tank and a Three.js skill pack for the agent to learn from. Swap the photo and the theme and it is yours.

```text
Hãy tạo cho tôi 1 trò chơi giả lập chăm sóc terrarium dạng 3D, có hình mẫu tương tự mẫu terrarium đính kèm. [your terrarium photo] learn from this skill https://github.com/majidmanzarpour/threejs-game-skills

create a playable game. don't stop till you make it.
```