Set against the vibrant backdrop of a 1960s-inspired, retro-futuristic world, Marvel Studios’ “The Fantastic Four: First Steps” introduces Marvel’s First Family — Reed Richards/Mister Fantastic, Sue Storm/Invisible Woman, Johnny Storm/Human Torch and Ben Grimm/The Thing — as they face a daunting challenge. Forced to balance their roles as heroes with the strength of their family bond, they must defend Earth from a ravenous space god called Galactus and his enigmatic Herald, Silver Surfer. And if Galactus’ plan to devour the entire planet and everyone on it weren’t bad enough, it suddenly gets very personal.