Gadgets
Remote Electrical Charge: A taser beam, the Remote Electrical Charge gun can be used to power machinery, create electrical fields to solve puzzles, and electrocute villains (non-lethally of course, because, well. Batman.)
Freeze Blast: Taking a cue from Mr. Freeze, the Freeze Blast is a projectile that creates ice platforms in water and freezes enemies in their places. Batman can then "break" the frozen villains, which doesn't seem to involve any shattering of internal organs or severed limbs, so it's really more like "pushing villains over while they're really cold." In the video, one Freeze Blast hit up to three villains at the same time, making it useful for rowdy crowds.
Villain
Deadshot: As part of a side-mission, Batman will track Deadshot as he systematically assassinates high-profile people within Arkham City, and then goes after Batman himself. Detective mode will be essential to finding and taking down Deadshot.