As others have pointed out, this game is a bit of a prank. For example, the "CONNECTIONS" value is randomly generated:

  numPlayers+=randomInteger(1,5)

Though there is indeed some WebSocket communication between your browser and the server. Here's what most of these communiqés look like:

  {"type": "leave", "id": 133334510518} 

I wonder why the author even uses WebSockets at all, or what these "leave" packets are meant for.