I see -- now I understand. There is no matchmaking server, unfortunately. Given the nature of our games, we've found that this simply isn't something that people make use of, and so there's no real point in having it. We did this with Tidalis, and Valley 1 and 2, and even though lots of people play the Valley games in particular, the matchmaking tends to be a graveyard simply because people play with friends. We can see tons of people playing on the Steam stats, but then the matchmaking is so empty that it makes the game look really unpopular... and it serves no benefit for players, since they just look in there and see nobody anyway.
Generally speaking if you want to set up a game in multiplayer, posting on the forums is probably the best idea.
Hope that helps!