Compelling story that is over all too soon
Graphics are outstanding in Batman, and the voice-acting is superb. Even Harley Quinn's over the top cheesy voice is ok as it fits in with her persona. My personal favorite is actually the voicing of Zsasz, as he slowly unfolds his life story to Batman over a series of side-missions. Unfortunately, those side-missions are nothing more than a series of running (gliding) to waypoints over the city within a time limit, in a shallow attempt to lengthen out the gameplay time. Since the main story arc is so compelling, you often find yourself bypassing these side missions to see what happens next in the story. Also disappointing is that if some side missions are too close to the main story arc, you may unintentionally trigger the main story arc when trying to get to a side mission, and then be forced to play the main mission. Also of note is that some of the side missions are downright irritating, from glide training that requires pin-point precision, to missions where you are given a general area of several blocks to find a body (or in one case, Mr. Freeze's wife), and then have to play a game of needle in a haystack.
Combat is fun and has changed little from Arkham Asylum. Mixing gadgets in with attacks is not only necessary at higher levels, but also adds some flavor to combat, which tends to become boring after several hours of simply pushing one button to attack and another button to dodge. Special takedowns and certain other moves are only available after building up an attack combo, which gives some additional incentive to not get hit while fighting multiple enemies.
Unless you are an OCD completionist, you quickly lose motivation to gather all the Riddler clues and complete all of the glide training, as you realize that you can easily complete the story without needing these things (the only exception may be the completion of the first three glide training missions, as that allows you to boost and glide off the end of a grapple line, instead of stopping. So my suggestion would be to rent this first and complete the fantastic story mode over the weekend, and then decide if you want to shell out the money to complete all the bells and whistles thrown in to distract you from the short story time.