3. "...And The Arkham Knight Is A Brand New Character" Uh huh.
Everybody and their mothers had a theory or two regarding the identity of the mysterious Arkham Knight and about 75% of those theories included Batman's long-dead sidekick, Jason Todd - the second Robin, who met his end following a vicious beatdown at the hands of the Clown Prince Of Crime. Jason eventually found his way back among the living (it certainly seems like a superhero hasn't had a proper death until they've attended their own wake), and took up the guise of the Red Hood - a vigilante favoring the more lethal style of shoot-em-in-the-face justice. Given the character's history, and the fact that he blamed the Dark Knight for his demise, Jason certainly seemed like the best fit for the Arkham Knight mystery, except for one small wrinkle - Rocksteady claimed that Arkham Knight was a "completely original character" designed for the game. However, it soon became obvious that Rocksteady weren't being entirely truthful, to say the least - it wasn't very difficult for any fan with a basic knowledge of Batman lore to deduce the Knight's identity after his first line, and when you couple that with the fact that Arkham Knight was the first game to directly address Jason's fate, it wasn't hard to do the math. The result was that by the time the big bad was unmasked, the reveal was mostly met with something more akin to an exasperated "ugh, really dude, REALLY?", than genuine shock. See, the problem wasn't necessarily that Jason Todd was under the mask, the problem was the fact that the whole question of who the Arkham Knight was had been built up as THE reason to play the game to the point that Rocksteady flat out lied to preserve the mystery. It's certainly understandable that they'd want to keep things under wraps, but all it served to do was cheapen the whole reveal and leave a stain on what was an otherwise fantastic retelling of Jason's story.