"It has actually been very well put together - Simon Kinberg and Matthew Vaughn worked on it together and they are both great at what they do. Then Bryan Singer came in, and, of course, he is Mr X-Men and he knows exactly how everything works. Just look at these first two X-Men movies: despite the huge cast of characters it all came together really well. These two movies never felt like overload and the balance was really, really good. On the other hand I though the third film felt crowded, but then Singer is excellent at working with ensemble casts. So with this one I feel it is all fine. I have read the screenplay and it doesn't feel rushed and it doesn't feel like it is too many characters."
He also added that, even with such a huge cast of characters, each superhero has their big moment, comparing it to Star Trek.
"I think the best comparison I can give is to Star Trek - that is an ensemble but it never feels as if there is not enough time with any one character. Or maybe Lost - that is an ensemble but every character gets their own moment to shine. So as long as everyone is there for a reason there doesn't need to be a problem with so many characters. This is a beautifully structured film, and it is a time travel story so the structure has to be especially strong."
X-Men: Days of Future Past is based on a comic book arc where the mutants are hunted by Sentinels in an alternate future. Mark Millar spoke about these gigantic robots, and where they fit into the story.
"I don't really want to give too much away but the Sentinels are a big feature of this story. They will be cool and this will deliver on all of the teasers. We've all been waiting for this ever since X-Men: The Last Stand showed us one of their heads. Now it is finally coming, and we only have to pay ten quid to see it in the cinema whereas they're having to pay $100 million to deliver it. So I'm delighted [laughs]."
We also reported last week that Ellen Page is returning as Kitty Pryde. While he wouldn't give specifics, Mark Millar revealed that Kitty Pryde fans will be pleased with this sequel.
"As soon as I say something it will turn into a big internet story. Let me put it this way though: Kitty Pryde fans will not be disappointed."
X-Men: Days of Future Past was released May 23rd, 2014 and stars Hugh Jackman, James McAvoy, Michael Fassbender, Jennifer Lawrence, Halle Berry, Nicholas Hoult, Anna Paquin, Ellen Page. The film is directed by Bryan Singer.