10 Video Game Secrets So Well Hidden Developers Had To Help You Find Them

Donkey Kong's easter egg may be the longest-kept secret in video game history, but the one in Arkham City takes the cake for completely missing its mark.

The secret involved the date-obsessed villain Calendar Man and his unique monologue, in which he teased the next two Arkham games. The secret was so elaborate that no one was able to find it even long after Arkham Origins was released, and Rocksteady developers were effectively forced to step in and tell the players how to find it. It turned out that the players had to know the date when Sefton Hill and Jamie Walker founded Rocksteady and then set their console clocks to that exact day. Only after that would Calendar Man drop his secret message.

The irony here is that this wasn't the first time an Arkham game's teaser missed the mark and required Rocksteady's intervention. Arkham City was actually teased by its predecessor as well, through a room hidden inside the Warden's office in Arkham Asylum. The room hadn't been found for more than a year, and Rocksteady had to drop hints about it to the fans.

It seems they never learned that their marketing tactics are a little too clandestine.