Hollywood actress Sandra Bullock said she enjoyed playing evil in a debut appearance as a villain in the animated film “Minions”.The movie, a spin-off of the “Despicable Me” franchise, focuses on the small yellow minions before they met Gru in the original film.Here the minions find themselves at a loss after accidentally killing off their evil masters. Three of them, Kevin, Bob and Stuart, eventually set out on a journey that will see them recruited by the villainous Scarlet Overkill, voiced by Bullock, who has her eye on Britain’s crown jewels.”It’s fantastic because she’s justified, she’s misunderstood,” Bullock said on the yellow carpet at the film’s world premiere in London on Thursday.”She’s an 8-year old little girl who’s throwing temper tantrums because she wants what she wants. But it was really fun to play” the Academy Award winner said.Despite her long career, the “Gravity” and “Speed” star said she found it difficult to maintain energy levels when locked alone in a sound booth.”It’s hard because I like having other actors to play off of or other minions to play off of and I didn’t have that,” she said.”So you really discover a lot of what you don’t know, you really rely on the director and the whole team that’s behind that sort of glass partition to help guide you.”The 50-year old said “Minions” may be her last voice role.”It was so hard and I don’t think it’s my forte,” she said. “I don’t think I’m as good at it as other people are. And if it worked out, great, I think this might be the last time.””Minions” opens in UK cinemas on June 26 and in the U.S. on July 10.