In the movie, for the fist time, we will see Ultron. Paul Bettany said that this is how it feels to be more than just a voice: "Uh, well, the main difference is I have to show up. You know, the great thing is being able to work with all these incredibly creative and talented people. However, I also now have to show up at junkets, you know, so everything’s a double-edged sword, you know?"
Mark Ruffalo was really silly with the answer to how he is able to find a way to make Dr. Banner feel like such a distinct character from the Hulk at the same time :"I was helped out by the fact that I’m green, and huge, to help me with the distinction between the two characters, so I can’t take full credit for that, except for the accent that I was using, maybe. I’m done."
Joss Whedon told us that one of the challenges of putting together the film was having so many characters: "There’s like 47 of these people. I really didn’t think that through, and I regret very much doing this at all. You know, it’s just making sure that everybody’s, you know, got their moment, that everybody’s got their through-line, that it’s connected to the movie. I have all these people. I love all these people. They’re extraordinary. But making sure that they’re not just all being served, but all within the same narrative structure, that they’re in the same movie, that it’s all connected to the main theme. At some point during the editing process, I could not have told you who they were, who I was, what movie I was making, I got so lost in it. But I think it all came together, and you know, it’s just about making these guys look good, which takes a long time"