So both me and my friend bought the game off D2D last night, and we've been trying to the a co op or even a multiplayer game running, but to no success. On both our ends, we can't join with the message "Warning, could not join game". I can't join other games on the multiplayer list as well, but on the co op list, there's a bunch of games with 2/2 people. So I think they managed to connect somehow.
Does anyone have a working solution (fort forward or etc)? Our last resort is to LAN this thing, but that's probably another whole week away before we can get together.