PixelRebirth was having problem with freezing during shooting as well. The plugin only uses UDP, but I put bullets and bullet's sounds over a reliable layer on top of UDP which runs slower.. I switched that to fast unreliable. I think the bug was with the sound though.
I hardcoded the game to port 5000 for simplicity. I added note to intro screen.
Once the bugs have been worked out/people have tested it I'll write a short readme and post link to plugin.
I updated link to new version! I'll be on beta chat for about an hour if folks want to test it out over internet: