If you have any issues that were explained at bug reports topic(https://itch.io/t/57111/bugsissues-on-demp) but you still complaining why is not working you have to keep in mind these things:
-Demp is created only by one person.
-its no easy to transform an non-multiplayer game into a multiplayer one.
-this mode has just been released there will be more future updates that will improve it.
-Demon is also very busy with his own game project so he works to multiple ones in the same time.
-Demp is just in early-early-alpha so don't expect any smooth performance (yet :D).
-stop asking stupid questions like:"how do i extract the file?" or "how do i start the game?" or "how do i load a save?" or even "how do i download the mod", this things are explained very well in this section:https://itch.io/t/56692/faq-frequently-asked-questions.
-stop asking when the mod its gonna release on linux or macOS, it will never be released on those platform becouse Demon is not working on this platforms and he don't know how to create the code for it.