Did all of you turn off "Fast memory"? It makes you unable to play as 3 or 4 if it's on. It's under System in the PPSSPP settings.
A screenshot to show where it is: http://i.imgur.com/k5BBseP.png
Since you are all using Tunngle, does it show a green smiley on the bottom right of the window?
https://www.tunngle.net/wiki/images//d/d...Legend.PNG
So your LAN IPs are IPv6 too or? If they are still IPv4 you can still port forward as you are used to because you assign your LAN IP, for me it's 192.168.1.2
But if you enable UPnP or NAT-PMP in your router then your router can do this for you. You will have to tell Tunngle to use UPnP if that's the case, I'm 99% sure I saw an option for it. More info here: https://www.tunngle.net/wiki/Port_Forwar...rt_Forward
A screenshot to show where it is: http://i.imgur.com/k5BBseP.png
Since you are all using Tunngle, does it show a green smiley on the bottom right of the window?
https://www.tunngle.net/wiki/images//d/d...Legend.PNG
So your LAN IPs are IPv6 too or? If they are still IPv4 you can still port forward as you are used to because you assign your LAN IP, for me it's 192.168.1.2
But if you enable UPnP or NAT-PMP in your router then your router can do this for you. You will have to tell Tunngle to use UPnP if that's the case, I'm 99% sure I saw an option for it. More info here: https://www.tunngle.net/wiki/Port_Forwar...rt_Forward