I know little about networking, but I was wondering if I were to make a 2 player 2-D shooter game (space invasion?), which networking model (TCP?UDP?) should I use? It's not a commercial game, just "the next step" thing.

From forum FAQ:

Quote:

Q3) Should I use TCP or UDP? A3) There are at least four different kinds of games as far as networking is concerned: Turn-based games, Real Time Strategy games, Role Playing Games, and Action Games. Briefly, if you're turn-based, you should go with TCP because it's simpler, unless you need peer-to-peer NAT punch-through. For RTS games, you're usually best off using TCP, although UDP can make sense in extreme cases. For role playing games, the story is less clear -- action-based RPGs with lots of kinetics, like City of Heroes, use UDP, whereas slower RPGs and MUDs often stay with TCP. For action-based games like first-person shooters or racers, you should absolutely use UDP.

The forums faq has some other advice on networking worth reading...