The game hangs for me (does not accept movements, only menu works)
when hosting the game. (and playercount is 0)
In Dedicated server I can fly around, but thats it.

Is there any trick to it? Or can it be that it does
not start while waiting for the multiplayer plugin to
start up?

Some small recent games of mine:
Griefer 4k http://damocles11.byethost9.com/griefer4k.html
Kobold 4k http://damocles11.byethost9.com/kobold.html
Cave 4k http://damocles11.byethost9.com/cave4k.html