I have been playing it since release and I guess with the Almond+ as my main router since April/May of last year and although there were some issues at one point around June/July of last year, I haven't had to open any ports or do anything to be able to play the game, so not quite sure what's going on in your case. It could potentially be your ISP doing some odd kind of port blocking, but that doesn't really make sense either.