You can't run in Python 2 (at least not with these instructions), since you are using `insert` to get the IP/is-hosting info rather than `raw_input` needed in Python2.
I tested the game now, both by starting two terminals and by commenting out the sender/receiver functions. I can move around. It would be good if you put the keyboard commands in the intro text (I found wasd and by reading the code I figured out you had to press Space to use the sword).
Interestingly, if you don't explicitly write "yes" at the start prompt, you'll still get into the game and can walk around (I even up in a battle with a blob) but you see no enemies moving and no other items moving on the map. Once I wrote "yes" it works. Looking at the code, this is because you are literally using 'yes' as a check later in the code. While this is not a good idea overall, you must at minimum validate user input like this and abort the game if the user didn't input what you expected!
Once I got it running by explicitly entering 'yes' , it works ok though. Mobs are tough and fast!
I see your game loop catches the `KeyboardInterrupt`, but using Ctrl-C didn't work for me on Linux; I have to kill the entire terminal to exit the game.
Finally, what M.U.D. are you referring to when you say that this is a "remake of M.U.D. for two players"? MUD is, well, a MUD. This plays more like Rogue or Moria ... Not a big deal, but the reference confused me.