10 Best Gaming Secrets Kept Before Release
7. The Sequel To Batman Arkham Asylum Was Hidden All Along
This secret was kept so well that nobody outside of developers Rocksteady knew about it until at least a year after Batman: Arkham Asylum's release!
It turns out that Rocksteady was already planning Arkham City before they finished Asylum. They were so confident that they'd be making City that they hid a completely secret room dedicated to the plans for Arkham City.
You'd never know about it unless you were either informed where it was or have a penchant for putting t explosive gel on all the surfaces just in case. The room in question is hidden in the Warden's Office of the Arkham mansion, and applying explosive gel three times to a completely normal-looking wall will blow it wide open and reveal the hidden room.
Inside there's a very obvious tease to Arkham City - a blueprint hangs on the wall with an area of Gotham City highlighted and an Arkham print directly on top of it.
Rockstedy continued on this tradition of teasing their next game in Arkham City too. If you go to talk to Calendar Man after setting your console to the specific date Rocksteady was founded, he will state 'I was there at your beginning, I will be there at your end.'
In Arkham City, he is indeed as Batman's end, as Bruce walks into Wayne Manor and it all explodes around him, Calendar Man can be seen watching in the crowd.