I would hope there's no combat challenges/achievements at least. I don't like to waste my time doing that, I prefer advancing the story and getting new surprises.
However, it would be sweet if we could play with multiple characters as we did in Arkham City. Mostly Batman, of course, with a little of Robin and Batgirl (though I hated her in that movie, I think Rocksteady can create the correct version of Batgirl)
I am undercover as a deaf person.