Yay for crappy routers

I found a game called Mega Man 8-bit Death Match today. Basically Doom with Mega Man. Singleplayer was boring, so I tried setting up a server. But the router seems to be against me.

NAT -> Port Forward
Port 10666 > Port 10666

Firewall -> Exceptions
Port 10666

Well, that's what I did for Teeworlds too. Teeworlds works. MM8bDM - not.
I tried running the server on my webserver, it took half an hour to copy everything over...
..."not enough RAM".