Say what you will about the whole Marvel package—I don’t know the last time I’ve had a blockbuster as nutty as Guardians of the Galaxy thrown at me, but the grand knitting of the cinematic comic-book universe makes this messy bundle of joy a breeze to watch. This weekend, millions of Americans will file into theaters to watch a zapped-out space opera where a talking raccoon is arguably your second lead, and they’ll eat it right up. Yes, there’s plenty of baffling talk of Kree fanatics and Infinity Gems and what have you, and the beating heart of the movie is a walking tree who can only say one thing, but Guardians of the Galaxy is so crisply-made and sharply funny that you immediately forgive any confusion.

Much of the credit for that should be laid at the feet of inventive writer/director James Gunn (who scripted alongside Nicole Perlman), a canny choice by Marvel to steer this unusual franchise to success. Unlike the costumed heroes of The Avengers, the Guardians are mostly unknown to the moviegoing public and do their adventuring in outer space among disparate alien races. There’s a lot of explaining to get through in this movie, and some of it barely seems relevant—but this is the Marvel Cinematic Universe. If it doesn’t seem relevant now, it’s probably going to play some part later. There’s a reason we meet the giant purple villain Thanos (Josh Brolin) here even though he’s only dimly connected to the main plot. It surely won’t be the last time we see him.

Gunn gets through a lot of storytelling as quickly as possible, and some of it’s a rush job. It’s never really clear why the wonderfully-named villain Ronan the Accuser (Lee Pace) wants to blow up a particular planet, nor why two of Thanos’ assassin daughters (Zoe Saldana and Karen Gillen) are in his employ. It doesn’t really matter. Ronan is up to no good, and he is interested in a silver orb that space-scoundrel Peter Quill (Chris Pratt) just rumbled from a distant planet. Quill is a displaced human whose abduction we witness in the opening minutes and now makes low-level trouble across the universe. He’s here to grab us by the collar and whisk us through this dizzying, but incredibly satisfying escapade, and Pratt, from his first second on-screen, proves he’s more than up to it.

He’s buffed out and chiseled now, but he has that same lovable golden retriever expression that won us over on Parks & Recreation, and he radiates thermonuclear charm in every scene. His nominal love interest is Gamora (Saldana), who is sent to retrieve the stolen orb, but Pratt has chemistry with pretty much anyone he shares the screen with. His presence is that winning. Guardians of the Galaxy charts Quill as he unites a rag-tag group of mercs—including the uni-phrasal talking tree Groot (voiced by Vin Diesel), the phlegmatic Rocket Raccoon (Bradley Cooper), and the stone-faced, literal-to-a-fault bruiser Drax (Dave Bautista, who exhibits surprisingly deft comic timing). They have some hero business to do, there’s some whining about it, but of course we know they’re going to come through in the end.

You can certainly accuse Guardians of sticking to a well-trod formula—but it hits the beats so perfectly, and throws in enough clever one-liners and knowing gags to feel like it’s in on the whole experience. Gunn is perhaps the most unique voice slotted into the Marvel formula—his previous films Slither and Super were sometimes-brilliant, sometimes-brutal genre mashups—and maybe it’s because of him that the plot strings seem a little more visible. But then he’ll throw out a surprising visual or twisted joke—Groot unfurling his oaken tendrils to flood a room with glowing flowers, or Rocket insisting that Peter steal a man’s artificial leg—and every time it makes Guardians feel a little more special than the Marvel films preceding it.

The action is sloppily done and over-cut, but that is not exactly news for any Hollywood blockbuster (the 3-D is also completely disposable). There’s some very agreeable space battling, but also a lot of choppy hand-to-hand fighting and explosions that are pretty quickly forgotten. But anytime the characters are bantering, or the roaring ‘70s soundtrack is playing, Guardians should get you grinning. There’s chemistry at work here that can’t be faked, even by the impressive Marvel apparatus. Each time Peter and the gang’s plans chaotically fall into place, it’s obvious that Gunn and his cast have something special going on.