20th Century Fox's Rio, which featured a split-second image of one of the avian protagonists of Angry Birds, as well as the numbers "13-12." A few of the game's more dedicated players have cracked that riddle -- firing off the birds in a specific sequence and direction on said stage unlocks a special, Super Bowl-themed level, provided you've updated to the most recent version of the game.
Check out a video after the jump to see how the bird-firing maneuver is properly executed. Also, we'd like to see more video game easter eggs in television commercials, please. Trust us, ad executives, it's good for you too -- we must have watched that freaking Rio commercial like, twenty times now.