not too bad, man
Gotham city looks marvelous and you glide, climb and grapple all over the rooftops and streets. You can only go in certain buildings, but they all have great atmosphere. Batman is equipped with lots of gadgets you need to make your way around in them. It plays a lot like a Zelda game in that sense. The combat is more like a 3d streetbralling game, with gangs of thugs teaming up against you. There are also boss-fights. These are a lot of fun, but not too challenging.
The Wii U version of this game includes the Catwoman and Harley Quinn's revenge downloadable content. It also makes a lot o fuse of the gamepad. You use the gamepad to select gadgets, look at your map, sonar, scan the environment for clues, manoeuvre the "batarang", break computercodes, trace calls and more. You can also play the entire game on it, making it the best version of this game available.
There's virtually no framerate drop as mentioned by "professional" reviewers.