This is a very simple experiment in socketIO that allows multiple simulataneous client connections. The game uses HTML5 Canvas to render graphics, and socket.io with node.js to do all logic server-side. The only things handled client side are rendering and input handling.
Switch out a single array for data and rendering for two arrays- one that has complete data (or an object) and an array that is modified every time someone disconnects or connects that has easy rendering data in a way that is fast to iterate through.
Make the starfield generated on the server and passed through on connection.
Add chat functionality.
Add parallax starfields.
Add a directional pointer that points in the direction of an object- could start as a social feature, but this can be the beginning for quests and stuff.
Add more ships!