Chennai: Actor Shirish, who describes the unexpected success of Tamil thriller "Metro" as rewarding, says it has boosted his confidence to continue experimenting without worrying about the outcome. "We never anticipated such an overwhelming response. We thought the film might have a decent run, but we definitely didn't expect it to create this kind of an impact. Although a small film, the way audiences have received it, has made it big," Shirish said. Directed by Ananda Krishnan, it has been three weeks since "Metro" released and it is still going strong at the box-office. "The film's success has boosted my confidence and helped me understand what audiences seek from films nowadays. I've realised that it's possible to make a socially relevant film in a way it will appeal to public, without being preachy," he said. While the critics and audiences loved the film, appreciation has also come from industry peers. "The most unexpected appreciation came from director A.R. Murugadoss and M. Sasikumar. Actor Vishal called and appreciated my work and even tweeted positively about the film," said Shirish, who has already earned the sobriquet 'Metro anna'. "In the interiors of Tamil Nadu, people couldn't pronounce my name right. Hence, they started calling me 'Metro anna (brother)' when I went on theatre visits. I didn't mind because it only shows how much they've accepted the film," he added. The success has added "pressure" on Shirish to keep up the good work. "The fact that audiences have accepted me means a lot. They made me responsible and I should live up to their expectations by continuing to experiment," said Shirish, who doesn't want to restrict himself to hero-centric scripts. "Any character with scope for acting is fine by me. I want to establish myself as an actor and not get caught up in the hero image. I like to take up roles that challenge me and push me to experiment. I don't even mind playing a negative character provided there is scope to perform," said Shirish, whose latest passion is singing. He has crooned a song in upcoming Tamil tele-film "Thaal". "I've composed and sung nearly half a dozen songs. One my friends who heard my songs requested that I sing for his film and I thought why not. The track has been received very well,a he said.