The “Sonic the Hedgehog” film franchise is growing fast — much to the delight of James Marsden.

The actor returns as the title hero’s best friend and mentor in “Sonic the Hedgehog 2″ and says audiences can look forward to a movie that dials up the action while adding fan-favorite characters Knuckles and Tails from the video game series.

“We find Sonic growing up a little bit, and we see shades of him starting to become a teenager and everything that entails,” Marsden said. “Pressing the boundaries a bit more than he normally does, sneaking out at night and trying to be Batman, or Blue Justice as he calls himself.

“He wants to use his powers for good, but he’s still a little young to be doing it and rough around the edges.”

The movie picks up after the lightning-quick Sonic saved Earth in 2020′s original film by defeating Jim Carrey’s power-hungry mad scientist, Doctor Robotnik. In the sequel, the alien hedgehog must work again with Marsden’s Tom Wachowski — the sheriff in their small town of Green Hills, Montana — after Robotnik returns with a fearsome new ally: the ultra-strong space echidna Knuckles.

“Tom’s finding himself more in a father-son dynamic this time around with Sonic,” Marsden, 48, said of his character. “I don’t think he was ready for that, but the relationship (going) from buddies to the sort of father-son thing is this slow evolution.”

The first “Sonic the Hedgehog” was a smash hit, making more than $300 million at the box office to kick off a movie series that already has a third film in the works.

The feel-good flicks add a new dynamic to a wildly popular Sega franchise that has featured dozens of video games, beginning with 1991′s “Sonic the Hedgehog,” in addition to multiple animated series, comic books and countless toys.

Marsden, who previously portrayed Cyclops in the “X-Men” movies, remains blown away by the magnitude of the Sonic fan base.

“I obviously knew the game, but I was not aware of how international and global the love is for this character, those fans who adore the character, love the game, grew up on the game,” Marsden said.

“I’ve been doing this for almost 30 years now, and with the exception of ‘X-Men,’ I haven’t really been a part of something where there was a No. 2 and a No. 3, so to get to do a sequel was one of those rare, special treats.”

Working with Carrey again was also a thrill for Marsden, who says the comedian arrived to the movie’s set every day brimming with ideas for how to depict his eccentric villain.

“This time around, he’s even more unhinged and maniacal, and I don’t think I’ve ever seen him have as good a time playing a character as I see him playing this character in this movie,” Marsden said.

“I spent a good portion of my life mimicking (Carrey), doing impressions of him and trying to do his stuff, so for me to be able to be on the set and to be sharing scenes and be on the big screen with him is a real bucket list treat for me.”

The “Sonic” sequel is Marsden’s first release in what should be a big year for the actor. The third season of Netflix’s dark comedy “Dead to Me,” which Marsden stars in with Christina Applegate and Linda Cardellini, and the Disney movie “Disenchanted,” which serves as a sequel to 2007′s fantasy comedy “Enchanted,” are both expected to premiere this year.

Marsden is looking forward to celebrating his new projects throughout the year, starting with a “Sonic” movie he believes anyone can connect with.

“It won’t feel like there’s any stakes unless you have a character the audience can relate to,” Marsden said. “Sonic, as super powerful as he is, there’s still a lot of things he hasn’t figured out yet.”

If you go

SONIC THE HEDGEHOG 2

PG, 122 minutes

Playing at Niantic, Mystic Luxury Cinemas, Waterford, Stonington, Westbrook, Lisbon, Madison.