Watch: Batman: Arkham City Easter Eggs Video
Though Batman: Arkham City is a few years old, above you can check out an Easter Egg video in case you missed something, if you have never played the game or if you just want to check things out.
The next Arkham game, Batman: Arkham Knight, comes out this Summer.
About Batman: Arkham City:
When night falls on Gotham and the seedy undergrowth of the city emerges, Batman is there waiting. Ever vigilant, the Dark Knight monitors the city he protects from high above the gritty streets. No one knows his deepest secret — except Dr. Hugo Strange. With Gotham's criminally insane, vile villains and insidious characters confined within the walls of Arkham City, Batman must fight to ensure his true identity remains hidden from the citizens he vows to protect.
The Dark Knight returns to Gotham in the follow-up to the popular Arkham Asylum in Batman: Arkham City. Soar inside the heavily fortified walls of Gotham's new maximum security home to explore this all-new world that is five times larger than the Asylum. Glide, soar and grapple through the City as you engage in hand-to-hand combat against enemies or take advantage of Batman's trademark stealth maneuvers. Experience the intense, gritty atmosphere with a brand-new storyline that brings together a new all-star cast of classic characters and menacing murderers from the Batman universe. Utilize an array of new and enhanced gameplay features that put you behind the mask of the Dark Knight like never before.