I would honestly say that I think you should be allowed to tell the player to read the manual before starting, and that's it, but in other discussions, I believe it was accepted that having something like a text box for input was okay, as long as it was not modified by the game (hence, input only).

In your case however, I can see where an interface for making a connection is definitely a good idea. That said, think about how to make an interface using only 1 bit of output. A long tone means connected, a short tone means type the IP address again, or type "host" to host. Something like that?

let me know if you agree, but I think it comes down to what's necessary. if you're making a multiplayer game, then an interface to connect via IP is very hard to avoid. if you're making a game that posts high scores online, then the same goes for an interface (at the beginning of the game, before the gameplay begins) to add your username. same goes for anything else, so long as it isn't a part of the gameplay, and there isn't a good way to implement it in the game itself. for example, instead of an options screen, in some game it may be possible to simply add key presses to toggle the various options.

so, overall, I agree with you, with the caveat that avoiding the interface is impractical.