what blanky said ...
possible.
but, impractical.
I think you wish to make a "persistant" world. Such a thing requires
a dedicated server and a static IP address ... something that not too many new users have. NOTE: a server could also be just simply
your PC, but that would not be practical as a dedicated PC (server) because you might want to use it for something else. Also, still does not overcome the static IP problem, unless you have an expesive service provider ...
On the plus side,
you can still "code" one, and if you later get real money, you can port it quite easily to a server. By easy, I mean relative to starting from scratch