This is not an actual server that you can play Cube World on! This project's sole purpose is reverse engineering and documenting the packet protocol only. It should not be used by anybody for any other purpose.
As Steamworks.NET doesn't have a nuget package (and to avoid commiting binaries to git), you will have to download the standalone 13.0.0 release and extract the files from Windows-x64 into the CWT_dev_server/steamworks_net_libs folder before building.
Although I licenced this code under MIT, I took a zlib helper class from LastExceed/CubeworldNetworking which has no license listed, as such the license for that code is ambiguous.