Two words: Ryan Gosling. Well, we'd say that's all you need to know but there's so much more to 'Gangster Squad' than our favourite Canadian actor.

For a start, Sean Penn -- one of the Hollywood heavyweights of acting -- stars as badass gangster boss, Mickey Cohen. And as this new trailer shows, he's p*ssed. Really p*ssed. He's on a mission to take Los Angeles, Mafia-style, no holds barred.

WIN a Just Dance 4 prize pack including a Nintendo Wii

Alas he's got some worthy opponents from the Los Angeles Police Department in Josh Brolin's John O'Mara and Ryan Gosling's Sgt. Jerry Wooters.

The usual suspects of guns and glamour are present, with a slick coating of Jay-Z's track, 'Oh My God,' wailing throughout the trailer, timed perfectly with big explosions, sexy clinches and guns blazing.

While it is all gangster style (including a smouldering, sex kitten Emma Stone) in 'Gangster Squad', a softer side should be noted to the production's history. This material, along with the new key art this week, represent some of the first materials released since Warner Bros. headed back into the studio to re-shoot certain scenes after the Colorado 'Batman' cinema massacre in July this year. According to The Daily Mail, 'Gangster Squad's' "pivotal scene" previously involved a shooting in a cinema (with the film slated for a September release), but Warner Bros. pushed back the release date to January in order to change some of the pivotal scenes out of sensitivity to the situation.

To that note, 'Gangster Squad' will be in local cinemas on January 10.

And now (*drum roll*) please enjoy 10 reasons to watch the 'Gangster Squad' trailer.