Luanti

Luanti (formerly Minetest) is an open-source voxel-based game engine focused on modding.

Minetest server

Below is a basic configuration that will host a Minetest server on port 30000:

{
 services.minetest-server = {
   enable = true;
   port = 30000;
 };
}

With this configuration, a user named minetest will be created, along with its home folder /var/lib/minetest. All default Minetest configuration and world files are stored in /var/lib/minetest/.minetest.

The Minetest service will be started after running nixos-rebuild. It can be controlled using systemctl:

systemctl start minetest-server.service
systemctl stop minetest-server.service

Additional options can be found in the NixOS options search