Marvel’s Guardians of the Galaxy is such a fun ride, with great action, plenty of laughs, a ton of heart and perfect choices in music. It will have you singing along, and cheering for the snarky Rocket Raccoon and a talking tree named Groot.

During a conference at the film’s press day actors Chris Pratt (“Peter Quill”/”Star-Lord”), Zoe Saldana (“Gamora”), Dave Bautista (“Dax the Destroyer”), Michael Rooker (“Yondu”), Benicio Del Toro (“The Collector”) and Vin Diesel (“Groot”) were joined by director James Gunn to talk about what attracted them to this project, how liberating it is to not have to fit into the regular Marvel scheme of things, why Yondu is such a bad-ass, fighting the right attitude for Peter Quill/Star-Lord, the emotional journey of the story, the process for having the music organically come from and compliment the story, the physicality of these roles, why the movie references Kevin Bacon, and everyone’s favorite song on the soundtrack. Check out what they had to say after the jump, and be aware that there are some spoilers.

Collider: James, these are some fairly unknown characters, even though they exist in the Marvel comic universe. What attracted you to this project, to begin with? And was bringing these characters to the screen a daunting task, or was it liberating?

JAMES GUNN: It was, frankly, liberating. For me, I think I would have had a harder time trying to fit into the regular Marvel scheme of things. This gave me a chance to take what I loved about Marvel movies and Marvel comics, and create a whole new universe, which has really been the most exciting thing for me, in my entire professional career. When I was a kid, I was obsessed with different planets in the solar system, and I used to create, for every single planet, a different alien race with a certain kind of pet, a certain kind of house, a certain kind of water system, and everything. I would draw these pictures. I had hundreds of these pictures in a box. Really, to me, this is like going back to that childhood box and creating this fun universe.

Vin, did you ever have to do the acting exercise where the teacher asks you to be a tree, and did that pay off, now that you are actually playing a tree?

VIN DIESEL: When I was a child actor, I had the fear that I was going to be cast as the tree. This was a way to face my fears, and I’m delighted that I did.

Michael, who’s more of a bad-ass, Merle (from The Walking Dead) or Yondu?

MICHAEL ROOKER: You know what? They’re very similar in their nature. They are true believers in tough love. Merle with his brother, and Yondu with his lovely surrogate son. Yondu is pretty damn powerful. I don’t think Yondu would let Merle get close to him.

Chris, you’ve recently had your fair share of having to gain and lose weight for parts. Do you relate to your female colleagues and what they go through with media scrutiny?

CHRIS PRATT: Are you saying that I might be responsible for giving men body image issues? That’s the nicest thing anyone’s ever said to me! No, I’m sure I can’t relate to what females go through in Hollywood, but I do know what it feels like to eat emotionally. To be sad and make yourself happy with food, and then be almost immediately sad again, and then ashamed. Then, you to try to hide those feelings with more food. I know what that’s like. It’s a vicious cycle, and it’s a very real thing. So, I know what it’s like to have body image issues. I also know that, if you just work hard and you enlist the help of good coaches, and you are coach-able and willing to work hard, you can actually change that. I offer a course. It’s $4,500. Anyone who has these issues, just get a hold of my people, and we’ll set it up. I’ll walk you through it. I don’t really offer a course.

Chris, did you do any research, as far as the comics are concerned, to see how this all played out?

PRATT: I was aware of Guardians of the Galaxy, but James told me not to read any of them.

GUNN: You keep saying that! You overheard me telling [Michael] not to read the comics.

ROOKER: And I read them, anyway.

Then, how did you find the right attitude to play this guy?

PRATT: In terms of the attitude, and the whole process, on this one, it was about just trusting James, really, and taking big swings and sometimes falling flat on my face. The big challenge for me was just trying to ignore the embarrassment of being an actor. It’s a pretty embarrassing thing to do. You’ve got people pointing cameras at you and hundreds of people watching you, as you’re trying to be great. And often, almost every time, you’re not. Then, there’s one moment where you are, and the editor will go through all the shit to find it, and then you have the movie. So, the challenge is not finding the attitude, but it’s really just being open and willing to go for it and try different things, and having a director that you can trust. The attitude is not something that I intended or created. It was something that James intended and created, by getting me to try different things.

Chris, you may not be who everyone imagines taking on a huge superhero movie role like this. What did you feel that you had to prove, even in the auditions?

PRATT: I’m not sure that I even saw myself in this kind of a role. What’s really nice about this movie is that I believe we did something that’s never been done before. This is unlike anything that’s ever been done. I think anyone who has seen this movie will agree. I’ve never seen anything like this before. I don’t think I was right to do anything that’s similar to what’s been done before. It wouldn’t have been right to do those other movies. So, maybe people wouldn’t have seen me in this role, but that’s because they weren’t able to have the vision that James had for what this could be. He told me in the audition, “I’m just looking for someone to come in and own this and do their thing.” At the time, I had been having an identity crisis, as an actor. I didn’t know what I was, and whether I was an action guy or a comedy guy. I thought, “Maybe I could do a combination of both, but there’s nothing out there that’s like that. Maybe I have to develop something.” And my manager just kept saying, “Guardians of the Galaxy.” So, I said, “Maybe you’re right. Let’s go meet on it.” And then, James said, “I just want somebody to do their thing.” I had an idea what that thing was, and it’s that thing that I got to do in this movie.

GUNN: We had screen tested at least 20 people, from big stars to no names, looking for the right person because I really wanted somebody who could embody this character and take it beyond what was on the page, the same way Robert Downey, Jr. did for Iron Man, essentially. And nobody blew me away. Plenty of people were really good. Many people were great. But, nobody blew me away. And Sarah Finn, our casting director, really deserves the credit for Chris, in a lot of ways, because she kept putting his picture in front of me and saying, “What about this guy? Why don’t you meet with him?” And I was like, “The chubby guy from Parks and Rec?! That’s stupid!” And she kept doing it.

Finally, and I don’t ever really remember agreeing to seeing Chris, she was like, “Okay, after this guy, Chris Pratt is here.” I was a little mad. I didn’t want to see him. But then, Chris came in and started to read, and this is 100% true, within 20 seconds, I was like, “Holy shit! That’s the guy! That’s who we’ve been looking for!” He had this thing that was himself. Sometimes a role and a person are meant for each other, and that’s what I felt this was. I turned around and Sarah Finn was sitting behind me, and I was like, “He’s the guy! Chubby or not, he’s going to be in the running for the first chubby superhero, but he’s still going to be better than all the other people we had.”

This movie is very action-packed and very funny, but it’s also got a lot of heart. Can you talk about the emotional journey that you put the characters through, and exposing their vulnerabilities?

GUNN: The movie is about a couple of things. Number one, it’s about a son’s relationship to his mother and how that manifests itself throughout the rest of his life. That, to me, is an emotional thing. The second thing is that we live in a world where everybody’s supposed to be cool and act tough and put up fronts, and everybody is so cynical. There’s a cool contest, on the internet, for who can be the most snarky. And this movie is about actually allowing yourself to care and allowing yourself to give a shit. That’s a naturally emotional thing for me. And then, thirdly, I fell in love with these characters, as I was making the movie, and I fell in love with these actors, as I was making it. Just my natural sensitivity to that, and to characters, people and emotions, is something that automatically was expressed in the film. It’s a film about family.

James, the music plays such an important part in the film. A lesser filmmaker would have just tacked on the songs that they wanted to hear, but you found a way to make them organic and spring from character and story. What was that process?

GUNN: There was a script, before my script, but it didn’t 100% speak to me. I wanted to make some pretty major changes, so I rewrote the whole script. And the very first thing that I thought of was this idea of the Walkman and the cassette tape, which is really this character’s connection to his home planet of Earth. If the MacGuffin of the film is this orb that everyone’s chasing after, the emotional center is this Walkman. And so, it was just a natural part of the screenwriting process. All the songs that you hear in the movie were all written into the film. They’re all part of the screenplay. They were there from the ground floor up.

Zoe, Gamora and Neytiri are both bad-asses, but other than that, they’re practically opposites. Can you compare and contrast the two, and your approach to them?

ZOE SALDANA: I feel they’re very different. Neytiri grew up in a household where she was loved and she was held, as a child. Gamora was taken, much like the lost boys of the Sudan. She was taken from her village and from her planet and forced into a life of violence and crime. There’s this pain that follows her wherever she goes, but there’s this last hope that she can possibly get away. So, I did try to find some similarities between them, but I don’t think they would play together in a playground. Gamora’s a hustler. Neytiri doesn’t even know how to lie. And I wanted her fighting technique to be very, very different. When you’re the last person cast, everybody is just ready to go. The stunt coordinators have already designed the fights, and they already have the stunt women working on what you’re going to do. And you come in and add any last little tweaks that you can. I just didn’t want Gamora to look like any typical action person that’s very martial arts-y and does those underworld jumps and lands, where the ground breaks and shit. I wanted her to be a little more graceful and antique and very classy, in the way she fights.

I was doing research for Gamora and one of my husband’s colleagues was showing us her last collection of work that she was going to show, that wasn’t yet ready for the public. She basically recorded this bull fighter from Spain, dancing a duel and leading the bull with his sword and cape. She shot it at 60 frames per second, so it was very slow. And I’ve never seen somebody move so smoothly. It was just such a seductive dance, and I thought, “Well, that’s Gamora.” She’s a woman, and she just has to be very seductive in the way that she tricks her enemy into falling to their own death. I’ve never done that. So, when I told that to James, he said, “Oh, yeah, go for it!” But, it was hard telling the stunt people because they think that girls are stupid. When you walk into this testosterone-driven rehearsal place and you’re like, “Well, she does fencing and she’s a bull fighter,” they were like, “What?!” Then, they realized that they didn’t really have a choice, and they adapted.

GUNN: I remember I got five messages from [Zoe] on different platforms, after she came up with this bull-fighting idea at 3 am. I got a message on one phone, and then I got a message on my other phone. And then, I got a message on one email, and then on another email, and then a direct message on Twitter. I was like, “I get it, you want to be a bull fighter.”

Benicio, The Collector is an unusual character. How did you approach that?

BENICIO DEL TORO: Well, James made me feel like I could explore it. I worked with four actors, and two of them weren’t there, so I had a lot of fun with Chris and Zoe. What I do remember was that I felt like I could explore the character every way that I would have wanted to. James was very supportive of taking chances and trying different things. I felt like an animal that was holed up in a cage, and then you suddenly open the door, and he comes out and is tentative. James was very, very nice to me, to allow me to just go. That was a great feeling.

GUNN: Benicio is one of my favorite actors in the world, so I was excited that he did this. And one of my favorite moments of the whole movie is when Benicio came into my office and sat down with me. He was visiting for his fitting. And we were talking about the character and how he saw the character and where he was coming from. And then, he said, “When I was a little kid, I was the first kid in my neighborhood to have a pet alligator.” And I was like, “This guy is my friend for life.” That was the best thing I had ever heard.

Chris and Zoe, can you talk about the physicality of the role and preparing for the fight scenes?

SALDANA: Actually, I stepped down from the training. I’ve done so many action movies. Last summer, I was like, “Oh, my god, I’m in love. I just want to chill and go to Italy and Boston.” And then, all of a sudden, James called and was like, “Hey, do you want to be in Guardians, be green, work six-day weeks with five-hour make-up sessions, and be an alien again.” I wasn’t sure, but I did it. Once I figured out where she was going to be spiritually, there’s muscle memory with all the things that I’ve done, the past seven or eight years. I was able to relax with my body and work with the stunt coordinators, unlike on other films that I’ve done. I remember that it was really funny because Chris was like, “I know that you’re very stunty and agile, but just be yourself and go with it.” But around the third take, he was like, “Just take it easy on that. There’s your mark, baby. Just stay on your mark. Don’t go over because, when you kick me, it hurts.”

PRATT: Yeah, she wacked me really good, a lot of times. She can knock you out, I guarantee it. She’s a real athlete. She’s got a very strong kick. She’d hurt [Vin] Diesel, too.

ROOKER: You were always saying, “A little harder! Go harder!”

PRATT: No! He punched me so hard, twice, in the movie. I don’t even know if it made it into the movie. It was so hard that I felt my organs shake. I had Rooker knuckle prints on my body, but it helped. It’s the best acting that I’ve ever done.

GUNN: Rooker and Chris hit it off, immediately, and the three of us would hang out a lot in my house in London. When they first met each other, they started talking about all these things that they have in common. They’re both a couple of hicks. So, they were sitting there, talking and really getting along, and Chris was this wide-eyed kid. He was like, “You know, we ought to go hang out and get to know each other, in that father/son way, so that we can bring that into the movie.? And Rooker said, “Nah.”

PRATT: That planted the seeds. I was like, “Oh, my daddy doesn’t love me.”

Vin, Dave and Benicio, what is the appeal of the Marvel universe and particularly this new off-shoot?

DAVE BAUTISTA: I didn’t look at it so much as Marvel. I was very familiar with Marvel, obviously, and of course, I realized that they had the winning formula and that their movies were very well done. But, I really looked at this as something new and completely on its own. It’s just original and fresh. I looked at it from strictly the standpoint of Drax. Once I realized who Drax was and how much of an emotional roller coaster his character would be on, I just fell in love with him.

DEL TORO: I’ve done a lot of movies, and you really never know. You do a movie and you think that it’s great, and then you see it and it doesn’t work. This is something that is the opposite. I loved working with everyone, and then the final product was a great movie that I really enjoyed. I got pulled in, and I think the credit is to everyone involved, and James because he just really did an emotional thing. All of the senses are tapped. I really, really enjoyed it. I’m very happy to be in a good movie, and any actor will say the same thing. That’s my feeling on it.

DIESEL: I’m new to Marvel. This whole thing started for me with a social media wave that was adamant about me doing something with Marvel, but there really wasn’t a six-month window to do a character at Marvel. So, when Kevin Feige called me and said that he and James were talking about me playing a role, I had no idea what role it would be. And then, they sent over a book of conceptual art, and I went into my living room with my kids and opened up the book, and I asked the kids what character they wanted daddy to play. They all pointed at the tree, so I knew that was a good sign. For me, it was at a very important time, when I did this movie, because it was in December, and it was the first time I was coming around humans again and working again. There was something very therapeutic, in my personal life and my professional life, after dealing with death, playing a character that celebrates life, in the way that Groot celebrates life.

I took my kids to a screening to see this movie, and now they walk around the house reciting lines from Star-Lord, Gamora, and all the characters. Something very beautiful happened in playing this role, that as an actor, I never would have imagined, and that is, when my kids see trees, they refer to the trees as my brothers and sisters. The idea of being associated with trees like that is remarkable. It’s so much more gratifying than you would ever imagine. I was really lucky that that specific role came up and that, when I went to breathe life into the role, I had a director that was willing to indulge in the way that he did. I felt like I was the last person there, so I got to see all of the performances, and I was so blown away by the performances. It felt almost too good to be true. And then, I was recorded the three words, day in day out, for four days. James sent me a script where the left-hand side of the page said, “I am Groot,” and the right hand side of the page would have a whole paragraph about what that meant. I walked into that situation and saw somebody that cared so much about every little nuance of that character. It was so refreshing that being a perfectionist wasn’t a bad thing. Unfortunately, in Hollywood, there are those directors that have some contempt for actors. We’ve all experienced that, in one way or another. To have a director that loves his actors is something that you can see in the film and in the fruits of that labor. You can see that translated in the film. When you watch this movie, you can see a director who loves his actors, and it shines through the movie, in my eyes.

GUNN: No one will ever understand, from the bottom of my heart, how much Vin Diesel brings to that role. I sat and watched the movie a billion times, with my voice in there and with my brother Sean’s voice in there. And when Vin came in and said, “I am Groot,” it really filled out that whole character. That’s really quite incredible. I couldn’t believe it, when we started cutting it in, because it made that character. That was a CGI character, suddenly complete. And it still doesn’t sound like Vin to me. It sounds like Groot. And there was a weird, strange energy in the room when he was doing it. A lot of people have felt, after seeing the movie, that Groot is this emotional character, and we even felt it while we were shooting. I’m eternally grateful for that performance, and a little freaked out by it.

James and Chris, can you talk about the Kevin Bacon reference? Are you a big Kevin Bacon fan?

GUNN: That reference led to some of the most fun moments in the movie. Chris and I have a very similar sense of humor. When you’re on set with me and Chris, it really is one long bit. A lot of the funniest moments in the movie were things that one of us started off, and then the other one added to, and then the other one built on that. And the Kevin Bacon reference was that. Chris came in and he said, “What if he thinks of Footloose as a legend?” I said, “That’s funny!,” and I started laughing. But, sometimes he would come to me with something that wasn’t so funny. I added the Kevin Bacon aspect to it, and he added something else. And then, we added the part with the Zoe and Kevin Bacon and the stick. It was just one of those moments. I happen to be friendly with Kevin because he was in my last movie, but I don’t think he knows yet that he’s in this. I’m really excited for him to see it.

PRATT: Yeah, that sums it up. It’s true that we have a sick sense of humor, that’s the sense of humor that, if someone were a fly on the wall, they would maybe think that we were mass murderers.

With such a great soundtrack, what is your favorite song in the movie?

GUNN: One of my favorite songs of all time is, “I Want You Back,” by the Jackson 5, which is in the movie. My favorite song in the movie, strangely is, “Come and Get Your Love,” by Redbone, which is when the whole idea of the mixed tape started cementing.

ROOKER: I don’t know music.

PRATT: The music was one of the first things that I requested, because it is the emotional center of the character and this movie, and Peter Quill has been listening to this thing non-stop, his entire life. I have a few albums like that, in my life, where I know all the words, and I wanted to be that familiar with the music, by the time we shot the movie. So, I had it sent to me and while I was working out, I just listened to it in order, on repeat, over and over. Some of the songs, I really love, and some, I really fucking hate. I incorporate sweating on the StairMaster to “If You Want Piña Coladas.” One song that really worked for me was “”O-o-h Child.” That has a beats-per-minute that’s perfect for my running pace, so that when I was running and that song came on, it put me at a nine-minute mile.

SALDANA: For me, it’s “Cherry Bomb.” I’m such a fan of The Runaways, and it’s when they’re finally getting their courage and their chutzpah to do something to save the day. It’s such a great song for them to prep to.

DIESEL: I loved all of the music. I had so much fun with the music. I thought it was such a testament to the movie. This is the closest Marvel will ever get to a musical. The movie starts with an emotional tone, very quickly, and watching Star-Lord kicking aliens makes you feel like you’re going to have a really good time. I’m singing the music, every day. Most of the time, when I walk into an interview, I start singing, “Hooked on a Feeling.” The coolest thing was when my three-year-old son was watching the movie, “Hooked On a Feeling” came on and he was at the edge of his seat. This is the first time that he’s ever gone to a movie, and that we’ve ever gone to a movie together.

Obviously, he can’t see Riddick, or any of the others. So, he scooted to the edge of his seat and he squinted, and then he started singing, “I’m hooked on a feeling. I’m high on believing.” Watching him do that, just melted my heart. So, we listen to the songs at home. It’s remarkable how a soundtrack can be so important to the storytelling and the experience. I think the music is going to make people see this movie a lot. The music is going to make you want to go see it again. You have so much fun in the movie, and it’s music that you want to share with your kids, anyway. It’s great because of that. So, I love all of the songs. I just thought it was an incredible collection.

BAUTISTA: After Vin, anything that I say is going to sound boring. I can’t sing. I don’t have any kids at home to talk about. Actually, my favorite song in the film is “Ain’t No Mountain High Enough.” It’s such a feel-good song, to begin with, but it’s also a feel-good scene. We finally come together. We’ve a family. We’ve all found each other. We survived, and we’re out to find some other trouble get into. It’s such a feel-good moment, and the song fits perfectly.

DEL TORO: I like them all. There’s a Bowie tune, “Moonage Daydream.” I like that one because it introduces The Collector.

Marvel’s Guardians of the Galaxy opens in theaters on August 1st.