Sandra Bullock's new film, Our Brand Is Crisis marks her first movie role in nearly two years

Credit: Jens Langkjaer

The day Sandra Bullock brought her son Louis home in 2010, she vowed to make him the main priority in her life. Since then, she has become more selective when taking on projects to focus on family.

Her new film, Our Brand Is Crisis, marks the first movie the Oscar-winning actress, 51, has done in nearly two years.

“I wasn’t looking for this,” Bullock exclusively tells PEOPLE at the Toronto International Film Festival. “I was having fun just being a mom.”

For Bullock to accept the role, she had to feel passionate enough about the film to bring her family into it.

“It had to be something extraordinary that would be a life experience for myself and my boy because he comes with me,” she says.

The film shows Bullock as Jane Bodine, a political mastermind called to help a Bolivian presidential candidate win his campaign.

Also starring Billy Bob Thornton, Zoe Kazan and Anthony Mackie, the film takes a deeper look into the world of politics and at the people running the show from behind the scenes.

“There’s an enormous national scope to the story we’re telling, but the beauty is that it’s a character piece,” explains director David Gordon Green. “You’re working with a group of people who fall in love with each other and the characters and I think that translates to the movie.”

Our Brand Is Crisis make its debut Friday at the Toronto International Film Festival, and will opens in U.S. theaters on Oct. 30.

For full coverage of the 2015 Toronto Film Festival – including the hottest premieres, the biggest stars and the buzziest films – check out, and