A glass tank of small animals, each one run by its own little circuit of simulated spiking neurons. They eat, flee, and change over generations while you watch. No script tells any animal where to go.
This is a bigger, standalone demo of the same terrarium idea: eleven species, thirty animals, real neuron models for the fly and the worm, day and night, speed controls. It's a separate single-file build, not the exact packaged room below (that one's simpler: three tools, built to run inside SandboxVille itself), but it's the same kind of simulation and it needs nothing installed. One file, opens in any browser, nothing sent anywhere.
Open the live demo →Get terrarium.zip below. Unzip it, you'll get a terrarium/ folder with room.json and a view/ folder inside.
Copy the whole terrarium/ folder into the rooms/ folder of your SandboxVille code, so the path reads rooms/terrarium/room.json.
Run the two commands on the right. The first prints its door sign in plain text. The second starts it so you can open it in your browser.
You'll need first: Node.js 22+ and a copy of the SandboxVille code. No folder and no network needed, this room is fully self-contained.