Basically, the same things apply as they would for an audio game.
It depends what mobile platform you're aiming for. I only developed audio games for Android thus far, and people always, always, always have issues turning off Talkback, which is essential if you want to have any kind of touch interaction and not use standard UI elements that Android gives you. However, it's well worth it. I keep putting tutorials everywhere on how to do it, so I'm hoping people noticed by now.
But other than that, it does not differ much. I put the same kind of work into my mobile games that I do for my PC games. Especially with the powerful devices nowadays, it shouldn't be much of a problem.
I have thousands of ways to implement menues and dialogs/scrolling text thought up in my head, so if that's what you're looking for, I can ellaborate more on that.