Hi I was able to get the internet networking operational by portforwarding my IP address. The setup we have is 4 games, 2 are based in Sydney with separate houses and external IPs. The other two of us live in the same house (thus sharing an external IP). The portforwarding works though the game cannot distinguish between the 2 of us that share the external IP thus allocating us the same character.
Is there possibly a way around this since the only other workaround we have is Hamachi which is very laggy.
May I suggest that you make it possible to host a Dedicated server? In a similar fashion to Terraria? this way, the portforwarding is far less complicated with less connection clashes.