Another movie now about to screen at Cannes - an animated adaptation of "Angry Birds", the highest-grossing game app ever. But why are those birds so angry? Good question, right? Well, the film attempts to answer that. We now meet some of the voices behind the "Angry birds" as they gather in Cannes.

The 'Angry Birds' movie cast gather in Cannes?

This Sony-Pictures offering chronicles the tale of the unpopular Red, as he tries to claim back birds' eggs that have been stolen by green pigs.

Josh Gad, who voices the yellow bird Chuck, said he was initially sceptical about the idea of turning the mobile app into a movie.

"You know when I first got told that they were making an 'Angry Birds' movie, I sort of rolled my eyes and said why? And that cynicism was quickly put to bed when the producer John Cohen did a five-minute presentation, and within a minute I was sold because the characters are so rich; the story answers this question that all of us who have played the game have never even stopped to ask: why are the birds so angry? It's subversive, but it's also got enormous heart," Gad said.

Raya Abirached said she added an Arabic twist to her character, the white chicken Matilda.

"In Arabic, especially in literary Arabic, we have opportunities to be a little bit more dramatic, you know, we're 'a la Egyptian'. So yes, I did exaggerate the over-the-topness of her. I had a lot of fun doing that, and hopefully our audiences will like that too," Abirached said.

For Gad, the development of his character was all about energy.

"Chuck is this speed demon, been there, seen it, done it all, kind of cynical about everything, and I loved that energy. I've never played anything quite like that, so that was sort of the inspiration for my choices," Gad said.

Producer John Cohen brushed aside concerns that the movie might have come too late to cash in on the popularity of the game, which was first launched back in 2009, but has since seen earnings slide.

"You know it takes time to make a great movie, and we weren't interested in just making a movie, we wanted to make a movie with a story that we believed in, with characters that we loved, and that was the most important. Animation takes a number of years, and we're very proud of what we have," Cohen said.

The film will hit U.S. screens on May 20th.