Critics are comparing Jake Gyllenhaal to Robert De Niro for his committed performance in the creep-out thriller 'Nightcrawler'. This isn't just because he lost 30 pounds to play the part, or that he injured his hand by spontaneously punching a mirror on set. It's because his character is such a sympathetic monster.

Jake Gyllenhaal as Lou Bloom in 'Nightcrawler'
Jake Gyllenhaal stuns critics with 'Nightcrawler' performance

Lou Bloom is an ambitious guy who is willing to do far more than it takes to be successful at something, anything. 'It was a challenge on the page', Jake Gyllenhaal says. 'It is a brilliant screenplay, but how do I bring this to life? Lou is not just a three-dimensional character. He's a six-dimensional character! He's so well-prepared, he's like the Bobby Fischer of manipulators.'

More: Read our review of 'Nightcrawler'

The trick was to keep the character relatively likeable, so the audience would travel this journey with him, even though he's utterly amoral. 'Actually, Lou's moral code is set by the internet, which means it's not about human interaction', the actor says. 'It's about electrical interaction, and he's at the controls. He deals with humans as if, in a way, they were computers he can control with a joystick.'

More: Watch the trailer for 'Nightcrawler'

Gyllenhaal says that the weight loss helped him find the character. 'I knew if I was hungry that I was in the right spot', he says. 'Physically it showed itself, but also chemically and mentally it was an even more fascinating journey.'

Since jettisoning Hollywood leading man roles in movies like 'Prince of Persia' and 'The Day After Tomorrow', Gyllenhaal has worked only with filmmakers who are willing to push him, such as Denis Villeneuve in 'Prisoners' and 'Enemy', David Ayer in 'End of Watch', and Dan Gilroy with 'Nightcrawler'. His next films include David O. Russell's comedy 'Nailed', Antoine Fuqua's boxing drama 'Southpaw' and the mountaineering epic 'Everest'.

More: Jake Gyllenhaal talks about his 'Nightcrawler' highlights