Well, you're unfortunately not really able to 'play', you can only walk around the world and talk to certain Npc's.
But yes, you should be able to do that with others, you have to set it up with your public ip or hamachi or similar (see the readme/the other post for that).
If you follow the last link i posted you can download a pre-built server that you can just configure, start and connect to (also see the readme/the otherpost for that)