Among the sneak peeks and previews at Comic-Con of films coming soon and not-so-soon, Robert Schwentke's Red managed to be one of the more promising surprises this year. Stars Bruce Willis, Mary-Louise Parker, Helen Mirren, and Karl Urban joined producer Lorenzo Di Bonaventura and comic creators Warren Ellis and Cully Hamner to premiere a new trailer, talk about the film, and pique fan interest in this odd, balls-out, exciting-looking new film.

But rather than merely recounting everything the panel participants said, we've compiled an abridged list of the stuff that was of most interest from the panel, and which provoked some of the most enthusiastic responses from attendees.

1. Moviegoers are guaranteed to get their money's worth from the movie. "I think over 75 movie stars are in Red," Willis revealed jokingly, explaining that the rotation of cast members made the production an unpredictable, fun experience. "Every day was fun. It was a really ambitious project and the work that the actors did became easier each week because every week we got another big movie star who came in that we were all excited about. I think that John Malkovich and Mary-Louise [Parker] and I spent the most time together, and it was like recess – it was so easy to do and so much fun to work with these actors."

Helen Mirren added that they recruited some real acting muscle: "They had The Queen, and then they had God," she said.

2. Even with her high-art pedigree, Mirren will be manning up just like the rest of the rough-and-tumble cast. "As an actor, those are the roles that you long for," Mirren explained. "You always want something that's going to kind of kick your last role out of the water and put you on a new path, and this miraculously came along for me. Bruce is sitting to my left and Mary-Louise is sitting to my right, but I was a huge fan of both of these actors so it was a great honor for me and somewhat intimidating to find myself acting with them. And also I guess the people who will go and see this film are not the people who will go and see a film about Tolstoy, so it's kind of nice to find a new audience, I hope."

3. Karl Urban not only worked but fought with one of his own acting icons in the movie. He said, "I've got to say I haven't had so much fun in years. It's not often you get to pick up one of the most iconic action heroes ever and throw him across the room and watch him smash into some furniture. He got me back for it, big time, too. It was a lot of fun. It was one of those situations where I got work with someone whose work I had admired for such a long time and then to actually work with him where finally all of my expectations of who he actually was were exceeded by the humble and generous actor that he is."

4. The creators of the comic book acknowledge that changes were made, but give the film their blessing and say they were definitely for the best. "My role was to stay out of the way," Warren Ellis said. "I said to the production team and the writers that I'm always there if you want to talk, but I want to see what you make with the film. I want you to make an adaptation, not a translation; it's yours now so go and have fun with it. But with the quality of the studio and the writers and the cast and the director, who the first time I met him came up and quoted to me from the first graphic novel I ever wrote in 1989 – which was so long ago for me that I had no idea what he was talking about – these are people who love comics and that there was little more that I could do other than just sit back and let them get on with it."

Cully Hamner, meanwhile observed that the story needs different things in different mediums. "The film is going to be different than the book," he observed. "The tone is a lot broader, I think. But when I visited the set, there were copies of the book everywhere, and that's a mark of respect, I think. I think that there's a lot of respect for what we did, even though they had to sort of broaden it a little bit for an audience, which I think was totally appropriate."

5. Although her training wasn't extensive, Mirren said she learned a few skills to pass on to her future audience. "I did some gun training, but that was it, really," she admitted. "The great thing about our job is that we find ourselves in these extraordinary situations and learning these skills that hopefully we'll never have to use. Certainly learning how to shoot a gun is something I had to learn. Of course I was surrounded by experts – not just people who were trained, but a lot of my co-actors knew how to shoot off guns, and all I had to do was watch them, really."

"But the most difficult thing about shooting a gun at least on film is not to have a silly face while the gun is going off," Mirren pointed out. "Because it's always a bit of a shock so you find yourself, you know, sort of sticking your tongue out. So the hardest thing was just to kind of keep a straight face while you are shooting a gun. Remember if any of you ever have to do that in a film in the future."