There is a ton of Sonic material to adapt, but the movie is best when it creates something new for Sega's franchise.
Sonic the Hedgehog has been around for nearly 30 years and there have been a lot of variations on the character in that time. His key characteristics are generally summed up as "runs fast," "is blue," and "has attitude." The Sonic we see in the live-action-meets-CGI Sonic the Hedgehog, thankfully, abandons the emphasis on '90s buzzwords for something a little more real and vulnerable. Sonic in 2020 is quick with a quip and a pop culture reference, but he's also just really excited to be here.
Sonic the Hedgehog foregoes pulling much from the video game and cartoon takes that came before it, choosing instead to set up something new for the character. Sonic (voiced by Ben Schwartz) in the film is something of a Superman character: an orphan with incredible power he's not quite sure how to handle. It's an interesting setup that the movie should have leveraged more, especially after a very brief opening that shows Sonic being chased from his home planet by a bunch of unknown bad guys for unknown reasons, who never come up again.
That backstory serves to get Sonic out of the video game world and into ours, where he's been hiding out for years, observing everybody in the small town of Green Hills from afar and wishing he could reveal himself and end his loneliness. In his frustration, Sonic accidentally taps into his latent super-speed-induced powers, and the resulting explosion alerts the US government to his existence. Cue an ET-like story of shady G-men hunting an alien, who then happens across a friendly human--local sheriff Tom (James Marsden), or Donut Lord as Sonic knows him from afar--who helps him evade the men in black and their maniacal, mechanically inclined leader, Dr. Robotnik (Jim Carrey).
Sonic the Hedgehog is really a buddy comedy about Tom and Sonic, and it's at its best when it leans into that dynamic. Schwartz is a perfect choice for this version of Sonic, who's a little irreverent and intensely tuned in to American pop culture somehow, but also earnest and upbeat. Schwartz's Sonic is more of a Michaelangelo from the Teenage Mutant Ninja Turtles than the combination of Bugs Bunny's mouth and Road Runner's feet that first hit the small screen in the '90s. It's something of an expansion of Schwartz's Parks and Rec character, the lovably enthusiastic but clueless and entitled Jean Ralphio, with Schwartz keeping the former parts and jettisoning the latter to make Sonic relatable but not annoying.
Marsden, meanwhile, avoids the formulaic position of the put-upon straight man in the comedy duo, instead quickly embracing the absurdity of making friends with a cartoon hedgehog and pretending Sonic is just a regular person in disguise. Marsden brings an easygoing likability to the team-up, selling that Sonic isn't as exhausting to be around as one might expect, and the two quickly establish a rapport that's a lot of fun to watch, whether they're just hanging out or actively fighting off Robotnik's many ridiculous robotic threats. Schwartz and Marsden are having a good time, so you are, too.
Surprisingly, Sonic the super-fast CGI hedgehog alien feels pretty down-to-earth in comparison to the movie's villain. Carrey is in full '90s effect as Robotnik, channeling the kind of intense goofiness that defined his more famously overwrought roles, like Ace Ventura, the Riddler, or the Grinch. It's hit-and-miss--Robotnik is so far over the top that you wonder why any other human being would put up with him, and he chews so much scenery that you have to wonder if the filmmakers were concerned people would lose interest in Sonic if they weren't constantly bombarded by Robotnik's weirdness. Compared to the more effortless humor that develops between Sonic and Tom, Robotnik feels out of sync with the rest of the movie; a bit of a tonal anomaly that's running at a slightly different speed.
Robotnik does have a few genuinely funny moments, but they're mostly the surprising ones that play against his established bully personality or show some vulnerability--like when he screams in the face of his assistant, Agent Stone (Lee Majdoub), but is actually giving him a loud and unnecessarily confrontational compliment. For the most part, though, Carrey's goofball intensity is aimed squarely at the younger kids in the audience, and his biggest moments feel transplanted from a different movie--as well as a bit tiring.
The movie is mostly about Sonic, Tom, and Robotnik, but a few other characters pop up to bring some laughs as well. Though she doesn't have a big impact on the story, there are some good moments between Tom and his veterinarian wife Maddie (Tika Sumpter), who gets to join in on the adventure toward its end. Maddie's sister (Natasha Rothwell) acts as pure comic relief in trying to convince Maddie to divorce Tom, and she gets a few of the script's better lines in her short screentime. It's a bummer that both characters don't get to play a bigger part in the story, but what time they do get adds to Sonic and Tom's dynamic.
Sonic the Hedgehog manages enough genuine humor, likable characters, and well-built action to be a fun ride, even though it is definitely intended more for a younger crowd than the aging fans of the game franchise. A couple of standout setpieces portray Sonic moving at a normal rate through scenes where everything else is stuck at a near-standstill, just like those Quicksilver moments in a couple of recent X-Men movies, and they carry some inventive slapstick gags that go well with the special effects. His one-liners are also deployed just often enough, and with just enough awareness, that they're funny without beating you over the head with try-hard references.
The movie is also knowingly reverential of the Sonic franchise without being beholden to it. Callbacks to the iconic music of Green Hill Zone or Sonic's foot-tapping idle animation from the game are enough to raise a smile, but the references avoid being glaring. Sonic the Hedgehog is a movie that knows its fans are in the audience and gives them quite a few nods, but mostly in subtler ways that work in the story, instead of dropping a bunch of pandering, neon-clad reminders that You Are Watching A Sonic Thing.
As video game adaptations go, Sonic the Hedgehog is among the stronger ones. It's smart enough to stand on its own, making use of longstanding aspects of Sega's supersonic mascot and his franchise, while making sure that what really shines through are its characters. That restraint goes a long way to making Sonic the Hedgehog a light, funny movie, and while it definitely skews young, longtime Sonic fans should have just as much fun finally seeing the Blue Blur on the big screen.