9 Video Game Secrets That Were Hiding In Plain Sight

2. Calendar Man's Rocksteady Riddles - Batman: Arkham City

Okay, these are just brilliant.

Indicative of just how much care and attention Rocksteady put in their games, you can visit the notorious Calendar Man in Arkham City, only for him to spin a huge amount of varying information, depending on which date your console clock is set to.

Christmas Day, Independence Day, Father's, Mother's, April Fool's - they're all fair game. However, three years after launch, a dummy Youtube account actually set up by Rocksteady themselves posted a video called "Arkham City Secret?"

It seemed there was one specific date that no one had thought of, and it set the fandom into a frenzy of clue-hunting.

The answer came from the fan channel "Batman Arkham Videos", who realised that if you punch in "December 13th, 2004" into your system, it triggers the last piece of dialogue from Calendar Man.

December 13th, 2004 is the date Sefton Hill and Jamie Walker founded Rocksteady Studios, and Calendar Man's dialogue describes their time working alongside the franchise:

"Well, well, well, and on today of all days. Do you remember my early work? Flawed, but it showed promise. Just like you. As your skills improved, I perfected mine. Starting with seasons, and moving through the weeks, I became stronger. My work more elaborate. Days were the secret, Batman. And the end of days is coming."

Best of all? He ends this monologue with "I was there at the beginning, and I will be there at your end" - a line many thought still referenced the developers.

Maybe it did, but look to the final scene of Arkham Knight's true ending though, and who's that in the crowd?

"At your end", indeed.