Thank you so much for your feedback. Sorry for the confusing descripton. This is not our first Game Jam, although it's the first Jam we managed to finish and delivery something playable (also our first time on GMTK Game Jam).
Yeah almost everyone who commented here told us about the very same problem with our multiplayer game. To be honest I'm trying to figure out why that was so big mistake, But I'm thankful you explained more accurately the problem behind it.
Again, thanks so much for your feedback, very much appreciated!