TORONTO -- James Marsden tries to avoid slipping down the rabbit hole of emotional darkness in his career -- and after the latest season of dystopian series "Westworld" the actor needed a palette cleanse.

It's one of the reasons Marsden says he signed onto "Sonic the Hedgehog," a live-action and CGI animated flick based on the popular video game. While his character in the film is veiled in secrecy, he insists it's nothing like Teddy, the robotic gunslinger he plays on TV.

"I always try and do the polar opposite of what I just finished, and 'Westworld' is a heavy show," he says of the series, which finishes its latest season Sunday on HBO Canada.

"You want to go do something else completely different."

Throwing some unpredictability into his career is something Marsden has attempted on a low-key level for years.

He's played Cyclops in the X-Men franchise, John F. Kennedy in "The Butler" and Liz Lemon's love interest on "30 Rock."

Later this year he'll join the ensemble of Quentin Tarantino's "Once Upon a Time in Hollywood," alongside Leonardo DiCaprio, Al Pacino, Brad Pitt, Margot Robbie, Burt Reynolds and Luke Perry.

Those roles are nothing like starring on "Westworld," a show with an online fan base that passionately debates its thematic elements, which include mankind's blind acceptance of technology and artificial intelligence run amok.

Marsden says he believes those conversations on message boards and social media are a "testament to the quality" of the writing and its underlying message.

"We like to embrace everything that's new but we don't stop and think whether or not it's good for us," he says.

But the actor admits even he doesn't know exactly where "Westworld" is headed because creators Jonathan Nolan and Lisa Joy haven't revealed to him the ultimate destination for his character.

"This is sort of an open-ended journey," he says.

"The exercise on our show is one of surrender because you know just enough -- but you don't know the ending yet. They'll give us some broad strokes."

As Marsden looks towards his next role in Sonic, he hopes his kids might warm to seeing their 44-year-old dad starring in the video game's film adaptation.

But he admits they haven't shown much interest in his Hollywood career.

"My kids are wonderfully underwhelmed with what I do," he says.

"It's not like they're begging me to be in movies, they've always found that kind of strange."

Years ago, he tried to get his daughter to watch the princess comedy "Enchanted," in which he plays the charming Prince Edward, but Marsden says she was perturbed by the whole concept.

"She didn't like me sitting next to her on the couch with me on the screen," he says. "It was a struggle for her to comprehend."

"They want you to be dad and not anything else."