With "Avengers: Age of Ultron" projected to do at least $200 million domestically - after opening to over $200 million overseas last weekend - it is clear that Marvel Studios remains hotter than ever, years after some movie pundits declared the comic-book movie craze over.

"We are under incredibly crushing expectations," Marvel Studios president Kevin Feige said in an exclusive interview.

Indeed, it says something that if "Avengers: Age of Ultron" does "only" $500 million domestically and $1.3 billion worldwide, it would be considered something of a disappointment.

This is because the "Avengers" franchise is the gold standard for Marvel, where everyone is excited to see them together and the group movies give the solo films a bump, which means more fans who want to see them when they all get back together.

Feige said that the formula for keeping the incredible synergy going between all the "Avengers"-related films is quite simple.

"A lot of it is based on storytelling," he said. "All of it is based on where we want to see these characters go and what stories we love from the comics and want to bring to life for the first time.

"Then the key is to have it be really entertaining and awesome when they're all together, and have it be really entertaining and awesome when they're in their individual films."

Feige also said that one of the keys is to do the unexpected and keep some things a mystery.

For example, at the end of "Iron Man 3," it looks like Tony Stark has decided to stop being Iron Man, but the beginning of "Age of Ultron" shows the team together, with Tony back in the suit, with no explanation about what happened in-between.

"There will be storytelling about that [in future films], as a matter of fact," Feige said. "In terms of Tony's . . . journey, the fact that he's having a hard time putting down the suit will come into play."

So will Stark's continued arrogance, on display when he created Ultron, which Feige said could foreshadow what gets Captain America and Iron Man to come to blows during "Captain America: Civil War."

"I think you could say 'yes' to that," Feige said. "Iron Man is still funding a lot of the Avengers' activities but will stop flying around in the suit. Thor we'll see in his own movie as he goes off to investigate what's going on. As I think people will see in 'Civil War,' the team is in good hands (without those two core members)."