More than anyone else, Lil Wayne has helped Southern rap become a big deal. Never mind Outkast: It’s the New Orleans–born rapper who’s enabled the subgenre’s takeover of commercial rap music. In fact, imitations of his stream-of-consciousness flow, off-key crooning, and Napoleon complex–worthy boasts might by now even constitute their own sub-subgenre.

But on Lil Wayne’s latest, Tha Carter IV—his first since leaving prison—he’s not only lost his swagger, he’s devolved into self-parody. On the spiritual follow-up to 2008’s blockbuster Tha Carter III, he’s become the boorish uncle at the family barbecue, annoying everyone with his bad puns.

Indeed, if you take out the often-uplifting production and the first-rate guest appearances, that’s all Tha Carter IV is: a series of bad puns. The grating jokes, ill-conceived similes, and groan-inducing metaphors come fast and furious. There’s “All hail Weezy/Call it bad weather.” And “All about my riches/My name should be Richard.” And “I send them Bloods at your ass like a tampon.” And “Don’t call me sir/Call me sir-vivor.” My favorite is probably this one: “How you niggas want to have it your way? Burger King/I get deep in that pussy, dig her out, surgery.” The first line contains perhaps the laziest pop-culture reference imaginable. The second is simultaneously ugly and nonsensical. Voilà!

Let’s take a step back: Wayne’s story is monumentally compelling. With both his father and his stepfather out of his life while he was still a child, he was more or less adopted by Bryan “Baby” Williams, who co-created what came to be pop music’s biggest independent label, Cash Money. Since then, Wayne has been a member of the supergroup Hot Boyz, been addicted to cough syrup, sold more records than just about anyone, and spent the better part of a year in Rikers on a gun charge. On Carter IV, our ears perk up whenever he offers even a taste of that story. “Only 2 years old when Daddy used to bring those hookers home,” he begins on “Megaman,” piquing our curiosity. Alas, he immediately elides into yet another too-cute play on words: “Looking like my grandma, my niggas got that ammo/We jack son then light up that L, Samuel.”

Since he got out of the can in November, much has been made of Wayne’s court-mandated sobriety. For a guy whose creative triumphs came during a time when he refused to enter studios that wouldn’t let him get high, a judicial injunction against weed and cough syrup constituted an artistic danger. But the early signs were good. The post-jail single “6 Foot 7 Foot” was a rousing good time, with its “Day-O (The Banana Boat Song)” sample chopped up by Atlanta producer Bangladesh in a rapid-fire way reminiscent of his pre-incarceration highlight “A Milli” from Carter III.

Critics who swooned over the grand scope and great fun in Tha Carter III and 2005’s Tha Carter II held out hope that IV would be just as good. But had they looked more closely at “6 Foot 7 Foot,” they would have been more skeptical. It’s not just the face-palm-prompting quips (“Swagger down pat/Call my shit Patricia”); it’s the dubious pseudo-intellectual turns such as the now-famous lines “Real G’s move in silence like lasagna” and “I got through that sentence like a subject and a predicate.”

Anyone who’s ever retired from serious weed smoking knows that your mind grows immediately sharper. You feel a renewed sense of self-confidence, and in social situations you lose certain inhibitions. That’s great for most of us. For Wayne, it appears to be his downfall. He thought he was clever before, but now he’s convinced he’s a genius, a profound linguist who could probably tell a devastating limerick if he tried. His insistence on repeatedly whacking us over the head with his nickel-ante jokes makes the first half of Carter IV all but unlistenable.

It does get better, thanks in no small part to a cavalcade of name guest stars. It’s a good bet most of them recorded their verses expecting IV to be a part of history and therefore brought their A games. The album’s last two tracks are its best. “It’s Good” features the sinister Jadakiss and a fired-up Drake, and “Outro” brings Bun B, Nas, Shyne, and Busta Rhymes together to spectacular effect. Rick Ross, meanwhile, continues his reinvention on “John”; the sheer pleasure he provides by way of his grunts and boasts might give him a strong claim to the Southern-rap throne. Wayne’s close to abdicating it, after all.

About the only time Wayne comes to life is on “It’s Good,” in which he addresses a perceived dis from Jay-Z. On the latter’s 2011 single “H*A*M,” he appears to take a shot at Wayne’s mentor, Williams, via a line about those with “baby money”—that is, less than what he has. “Talking about ‘baby money,’” Wayne responds here. “I got your baby money/Kidnap your bitch, get that how-much-you-love-your-lady money.”

Say what you will about the appropriateness of a superstar rapper threatening to ransom a superstar R&B singer—an image that’s more comical than threatening—but it’s an inspired couplet, with both an intricate rhyme scheme and an impassioned message. Wayne is defending his turf, standing up for those he loves, and directly challenging one of his main chart competitors. Unfortunately, he doesn’t do much of that on the rest of the album. Should there be a Tha Carter V, let’s hope Wayne gives his punch lines more punch.