Overview: When the manic Dr Robotnik returns to Earth with a new ally, Knuckles the Echidna, Sonic and his new friend Tails is all that stands in their way.

Verdict: Jim Carrey has announced that he’s leaving acting behind him. “Yeah, I’m retiring,” the actor, 60, told Access Hollywood. “I have enough. I’ve done enough. I am enough.”

Go with God, Jim. But the comedy great’s possibly final film, “Sonic The Hedgehog 2,” isn’t exactly going out on top.

Two years ago, the first “Sonic” was a surprise hit for Paramount even after a wave of bad press said the terrifying CGI hedgehog we saw in the trailer was the stuff of nightmares. The filmmakers gave the little guy a makeover and the movie made a respectable $319 million at the box office.

At that point, Sonic should have scooped up his magical golden rings and — like Carrey — called it quits. But, oh no, Hollywood’s ravenous appetite is never fully satisfied. And so now we have an often grating sequel that shoves in more of Sonic’s annoying animal friends.

In the formulaic plot, his nemesis Doctor Robotnik (Carrey) has been trapped on the Mushroom Planet (“Holy shitake!,” he yells) since the end of the last adventure, but manages to escape and help a rival red hedgehog named Knuckles (voiced by Idris Elba) find the legendary Master Emerald.

The gemstone, a cheap knockoff of the ring of power from “Lord of the Rings,” brings its owner’s thoughts — good or bad — to life.

Sonic (who makes his own lame swear joke, “Holy sherbet!”) must stop Robotnik while the blue dude’s bland roommates from fictional Green Hills, Calif., Sheriff Tom (James Marsden) and Maddie (Tika Sumpter), are at a wedding in Hawaii. For those of you who are curious which hotel is hosting the ceremony, the characters repeatedly remind us they’re at the new Four Seasons Oahu. What is this? Sonic the Ad Man?

Our hero is joined by Tails, a cutesy Fox with a helium voice like Tails on a chalkboard that would be more at home on a kids morning TV show than a cheeky live-action movie.

The whole enterprise is a textbook MacGuffin, a story in which the characters spend the runtime searching for a coveted object. The Master Emerald isn’t quite the Ark of the Covenant, and Sonic and pals don’t make too many exotic stops. Just California, Siberia and Hawaii. They don’t solve complex clues so much as stumble across buttons.

The first “Sonic” worked unexpectedly well because it thrust the wisecracking alien into a small town filled with humans — a hog out of water — and gave Carrey the opportunity to once again do the physical comedy he’s best known for. Now the novelty has worn off, the charms of the original have evaporated and there’s nowhere for the series to go.

Carrey is still a riot as Robotnik — which is a “Mask”-like role for him in that there is no emotion or heartwarming aspects — and he’s forced to hoist up high-budget mediocrity.