There's a secret room that belongs to Warden Quincy Sharp in Batman: Arkham Asylum
that has blueprints for Arkham City, which is the basis for the next game. Game Informer shows you the video
on how to access it. It takes three applications of the explosive gel for you to get into this area and there's no achievements nor does it count toward your overall percentage so it's kind of tough to find on your own. You can't even see a weakened wall and who would ever go around placing three applications of explosive gel on walls anyways?
Seeing this kind of gives me more respect towards Rocksteady. They had Batman: Arkham City
in mind from the get go and placed some concept art and the blue prints into the first game just to tease folks even though it's taken this long for Rocksteady to let people know of the hidden area and how to access it. You know what's going to happen now with Arkham City
. People are going to go around trying to find the hidden area that will give clues to the next Batman game.