At the risk of sounding like that guy from The Onion who appreciates the Muppets on a much deeper level than you, the Muppet movie prompt is strange because the Muppets re-enacting a classic work of literature on the big screen — or any story that’s not at least a nominal original — is almost entirely confined to the 1990s. The main exception is a small-screen variation on this formula, with the Muppets performing The Wizard of Oz for a 2005 network broadcast that featured Ashanti as Dorothy. Combined with the lack of an ongoing Muppet Show equivalent, those two theatrical releases and one TV movie seem to have propagated the misconception that the Muppets’ main job was essentially putting on school plays.

But as a recent special illustrated, that’s not the only show the Muppets know how to do. The three Muppet films made when creator Jim Henson was still alive — The Muppet Movie (1979), The Great Muppet Caper (1981), and The Muppets Take Manhattan (1984) — were largely reconfigured origin stories with plenty of meta winks. The Great Muppet Caper is the closest to the storybook movies in its conceit that Kermit, Fozzie, and Gonzo are obviously playing parts in a movie (and already know each other when the movie begins). But it still has the gang meeting and teaming up over the course of a narrative that’s a pastiche of old movies, but not a specific remake. While the other two films don’t mention The Muppet Show specifically, they both feel like they could be taking place prior to the creation of that program.

The Muppet Christmas Carol, the first film made after Jim Henson’s untimely 1990 death, is also chiefly responsible for the idea that Muppet movies feature an all-Muppet cast led by a single human. That’s not actually true. Like the others, Christmas Carol has plenty of humans. It’s just that Michael Caine gives such a terrifically straight-faced performance in the lead as Ebeneezer Scrooge, opposite such a great variety of puppet characters, that it’s easy to forget about the other human actors entirely. Muppet Treasure Island in turn plays like a sequel to Christmas Carol, repeating elements, sometimes to its detriment.

In Muppet Treasure Island, the faux-only human duties are split between two characters: Jim Hawkins, the young lead character of the Robert Louis Stevenson novel, and his mentor-turned-antagonist, the pirate Long John Silver. Initially, the filmmakers planned to turn Jim Hawkins into two characters played by Gonzo and Rizzo, reprising their double act from Christmas Carol. Ultimately, they decided it would make more sense to cast a genuine kid in the part, so Kevin Bishop would play Jim and Gonzo and Rizzo would be his sidekicks issuing commentary. This even more closely replicates Christmas Carol, where Gonzo plays a narrating Charles Dickens and Rizzo acts as his sidekick; they’re both constant (if unseen) companions to the main action. And as with the previous film, a beloved English actor would serve as a familiar face in an iconic role for Muppet Treasure Island, with Tim Curry playing Long John Silver.

These decisions made Muppet Treasure Island the second Muppet movie in a row where, rather than Kermit, Piggy, Fozzie, and Gonzo serving as the most prominent characters, the foreground would be occupied by Gonzo, Rizzo, a variety of story-specific Muppets, and the human stars. In some ways, this increases the ambition and invention of both films, which continue Jim Henson’s tradition of pushing the boundaries of puppetry. In Christmas Carol, the experiments are more serious, with the eerily childlike Ghost of Christmas Past and the traditionally menacing Ghost of Christmas Yet to Come not much resembling traditional Muppets. In Treasure Island, the variations are more comic, with a delightful menagerie of animals, misshapen pirates, and assorted weirdos, plus some classic Muppets mixed into a few supporting roles and cameos. Because the Muppets rarely turn down opportunities to break the fourth wall, there’s a fun moment where talking vegetables muse about the awkward way the Swedish Chef has been shoehorned into a particular scene.

It’s weirder, though, that Kermit the Frog doesn’t make his entrance until nearly half an hour in, and Miss Piggy doesn’t turn up until even later. That’s not to say there can’t be a Muppet movie that doesn’t star Kermit and Piggy, but at this particular point, six years after Jim Henson’s death, it felt as if the filmmakers were still overcautious about using a post-Henson Kermit. Rather than showcasing Steve Whitmire as the new Kermit performer, they gave more screentime to his established character of Rizzo. Nothing against Rizzo — he is a pioneer in the field of rat-centric food prep — but the children (and neurotic adults) yearn for Kermit!

The ginger use of Kermit is one of several examples of how Muppet Treasure Island catches both its characters and their then-temporary home of Disney at odd footing. Mere weeks after the release of Muppet Treasure Island, ABC would debut Muppets Tonight, a continuation of The Muppet Show that featured a mix of old and new Muppets (and that also put Kermit in a more supporting role). Several fan favorites (and obscure oddities) would emerge from this show, but not in time to appear in Muppet Treasure Island, which makes the movie feel a little grab-baggier in retrospect (though a few Treasure Island characters, like Polly the Lobster, subsequently appeared on the show, and plenty of Muppets Tonight characters made it into later Muppet movies). Kermit and Piggy aren’t in it much, but it doesn’t boast Pepe the Prawn, Bobo the Bear, or even 1980s newbie Bean Bunny, either. A lot of it really is given over to the human actors.

On the Disney side of things, the film’s middling songs — not without their charms, but the worst batch of originals in any Muppet movie — feel of a piece with the Disney animation of the era, which was coming down from its early-’90s Ashman/Menken high, and fast. This isn’t Disney’s particular doing. An initial deal for the company to acquire the Muppets fell apart in the wake of Jim Henson’s death, and wouldn’t come together again for another eight years after the release of Muppet Treasure Island, which it only distributed. But as a musical version of an oft-told story, it comes closer than any other Muppet movie to following the Disney animation template of that era. (Indeed, Treasure Planet followed six years later, albeit sans production numbers. And in retrospect it’s a little surprising that the Muppets aren’t cracking Pirates of the Caribbean jokes in this movie.)

Yet for some people, Muppet Treasure Island is close enough to Muppet Christmas Carol to feel meme-ably close to the Muppets’ whole deal. And it’s far from bad; it’s the Muppets doing pirate antics, so despite my carping it’s actually pretty fun. But 30 years on, Muppet Treasure Island being arguably the weakest of the Muppets’ eight theatrical features serves as a reminder that making a great Muppet movie isn’t as simple as plugging the characters into a clear and obvious formula. No matter how often the internet circulates it, they’re too sweetly unruly for that strategy to work.