The multiplayer games that use the computer as the server over the internet, is that hard to do? Just curious right now.
It's harder than not to do it of course... ;) Turn based games are relatively simple, because you don't have to care much about real time movement and fast enough transfers. Maybe even a simple http-based communication can be sufficient. That said, action games are a bit harder to do.
I've been thinking about trying a turn based http. I guess that would be the next thing to try after this game I'm working on. I think the thing to do would be to write a game that could handle maybe 5 to 10 players and then have it be able to run single player with bots and people could join or not. This game I'm working on could take quite a while so I'll have lots of time to think about it.