Love me some Arkham games. The gameplay is really in the sweet spot between accessible and challenging. But it's really the map design I think I like most. It's essentially a Metroidvania (and eternally, Metroidvanias are my favorite games of all time). Five or six districts/areas. Progression determined by the unlock of new abilities. Not a lot of arbitrary, non-useful items to collect.
They've gone overboard with the DLC, though. But hey, that's Batman for you.