NNG4
This is the lean4 version of the classical Natural Number Game. It uses the Lean4 Game Engine and is running live at adam.math.hhu.de.
The game was initially designed for lean3 and has been adapted for lean4. See lean3 version.
Getting Started
There are multiple ways to run the game locally:
Codespaces
You can work on it using Github codespaces (click "Code" and then "Codespaces" and then "create codespace on main"). It it should run the game locally in the background. You can open it for for example under "Ports" and clicking on "Open in Browser".
Note: You have to wait until npm started properly.
In particular, this is after a message like
[client] webpack 5.81.0 compiled successfully in 38119 ms appears in the terminal, which might take a good while.
As with devcontainers, you need to run lake build after changing any lean files and then reload the browser.
Local setup
VSCode Devcontainer
The full instructions are at Running games locally.
In particular, the recommended setup is to have docker installed on your computer
and then click on the pop-up "Reopen in Container" which is shown when
opening this project in VSCode.
You can then open localhost:3000 in a browser.
After making changes to the code, you need to run lake build in a terminal and
reload the web page inside the "Simple Browser".
Gitpod
Not verified to work yet.
Contributing
If you want to contribute to the Natural Number Game, it is probably best if you ask us for access and push on a non-main branch in this repo. That way a github-action will build the game automatically.
See the documentation for an explanation of the game commands.
Gitpod
You can work on this repository using Gitpod : 
Creating a new game
In order to create a new game, click "use this template" above to create your own game. That way there is a github action that can build a docker image from your main branch which can be used to add the game to the server at adam.math.hhu.de.
Development
Installation
The full instructions are at Running games locally.
In particular, the recommended setup is to have docker installed on your computer
and then click on the pop-up "Reopen in Container" which is shown when
opening this project in VSCode.
The game is then accessible at localhost:3000/#/g/local/game.