Let's face it, B-Man needs servers, so I wrote a guide on how to port forward the game so you can contribute to adding working servers to the game.
http://steamcommunity.com/sharedfiles/filedetails/?id=398108587
This isn't a fool proof guide so you might still have problems, but hopefully it can get a beginner started.
Secondly, please limit your player counts because I think 20 is too much.. it max player count may be limited next patch.
Also please, if you like the game, leave a nice review on the store page c: