Successfully complete the game to unlock the Armored Batsuit in Challenge mode.
If you are perplexed by The Riddler's more difficult riddles such as "What's right in front of you but still hidden from view?", you will usually be able to use Detective mode to find a piece of a question mark without a dot (or the dot without the question mark). An easy way to see an example of this is to go to the second balcony outside of the penitentiary. Look toward the medical facility, and enable Detective mode. You will see a "?" with no dot under it on the floor. Grapple to the balcony above, and on the center pole of the railing is the "?"'s dot. Align them onscreen, and use Environmental Analysis. This will solve the "Do you see what I see? No? Then maybe I am in a stronger position." riddle. There are only a few of these riddles, but you must find both parts of the "?" and align them to solve the riddle.
If you are skilled enough to find all of The Riddler's secret maps, or if you find all the "Chronicle Of Arkham" hidden pieces throughout the game without them, there will be one more blank chronicle remaining to decipher. To unlock it, go all the way back to where you found Clayface behind the wall in the penitentiary. Go up the center stairs where you left Warden Sharp a long time ago. There will be some scribbling on the floor. Use your Environmental Analysis on it to unlock the final chronicle.
When fighting a Titan henchman along with a group of normal henchmen, stun the Titan, then jump on his back, and use him to hit the normal henchman to increase your combo total.
Bane's primary attack is similar to the trample done by the deformed Joker henchman. When Bane begins to run towards you, throw a Batarang at him, then dive out of the way. Bane will run into the wall and will be momentarily stunned. While he is stunned, start hitting him. Batman will then jump on top of Bane and rip off one of the hoses pumping him with venom. If your Batarang misses Bane, he will still run into the wall and appear to be stunned; however, he will just cover his face and try hitting you. When he turns around, run away from him. After you rip off the first hose, prisoners will jump from the railings and try to help Bane, and Bane will throw chunks of wall at you. You can focus on them or just try dodging them while focusing on Bane. Pull three hoses from Bane's back to defeat him.
To destroy Poison Ivy's large plants on the ground, get near them to pull out the heart by dropping from above. Find a high point such as a tower or building, then drop down directly beside it. The plant will not have enough time to produce the irritating orbs that can hurt you before you tear its heart out.
There is an advertisement in the Medical Facility for the hospital's website (www.ArkhamCare.com). You can visit this URL in a web browser and use the employee login section. Enter "125845712" as the guard login number. You will login as Frank Boles and can read information about him.
You can find Ras' corpse in Dr. Young's office. If you re-visit the office later in the game, Ras Al Ghul's body bag has been unzipped and his body is missing, showing that he once again resurrected and escaped.
In Intensive Treatment, there is a long hallway (where Scarecrow first attacks you) where you will hear a recording that talks about how to treat patients. It tells you that you can find pricing information at http://www.arkhamcare.com/prices/, which is a real website.
In the Warden's Office, go back to the room with the Warden's portrait on the far wall. Turn left as soon as you enter the doorway, and approach the wooden wall. You can destroy it with Explosive Gel. It may take a few tries, but one of the panels on the wooden wall can be destroyed. Beyond the wooden wall is an unmarked room with a blueprint on the wall. It shows plans for the relocation or expansion of Arkham to Gotham City. This is a reference to the setting of Batman: Arkham City.
During the final confrontation with Scarecrow, it shows Batman's gravestone, which is the same design as the current comic book series Batman RIP.
After rescuing Cash and the orderly from the Joker's laughing gas, stand in the main room looking at the smaller room where they were trapped. A ticker will scroll the following garbled message: "Dr. Clooney report to Gynecology." This is a reference to George Clooney, who once had the role of Batman.
If you lose to Bane, it shows a cutscene of him snapping Batman's back over his knee. This is reference to Knightfall: Book 1, where Bane breaks Batman's spine.
Listen to the first Scarecrow interview. You will hear him mention a Dr. Murphy, and a Dr. Combs will be mentioned by a security guard. Cillian Murphy played Scarecrow in the newer movies and Jeffrey Combs voiced Scarecrow on the later episodes of Batman: The Animated Series.