Benedict Cumberbatch: Special Effects in 'Doctor Strange' Are 'Stunning to Watch' "It is extraordinary what they’ve done," he said of Marvel.

 -- Benedict Cumberbatch's new Marvel movie, "Doctor Strange," in which he plays an arrogant neurosurgeon who becomes one of the most powerful superheroes in the world, is already selling out movie theaters overseas. It’s a role Cumberbatch said was “great, great fun to do.”

“It was just incredible. This job first and foremost was an acting gig,” the Emmy-winning actor said on “Good Morning America” today. “He’s this extraordinary neurosurgeon and he’s kind of built a gilded cage without knowing it and he goes from that to a place of utter selflessness where by the end of the film, you’re looking at him on his own, choosing a path that’s about other people and you think, ‘Yeah, OK. You are now an Avenger. I believe that you’ll go join them.”

He also said the special effects in this film are “properly stunning to watch.”

“It’s extraordinary when you do these films because part of the special effects are the real world environments that Marvel creates around you,” he explained. “But I tell you what. I saw this for the first time at the LA premiere and it is mind blowing. It is extraordinary what they’ve done. It just melts the real with the unreal in a kind of seamless way.”

Cumberbatch, 40, is also keeping busy as a new father. His son Christopher turned 1 in June, and he and his wife, Sophie Hunter, are now expecting their second child.

“It’s amazing. It’s a game changer,” he said of parenthood. “It’s the best thing in my life. It’s just a joy.”

"Doctor Strange" hits theaters in America this Friday.

Disney is the parent company of Marvel and ABC News.