When I think about old Mario games, one of the first things that comes to mind are those beautiful world maps. The hypnotic bouncing of sprites, the highly underrated musical bops. The world map, introduced in Super Mario Bros 3. and a franchise staple ever since, is a way for Nintendo to weave a connective tissue between levels, and give them a thematic framing. It’s also not something that’s in Super Mario Maker or it’s sequel—officially, anyway.

If you’re willing to jump through a few hoops, however, it is possible to create a world map, and once you’ve played with one, its absence from Mario Maker 2 is all the more frustrating.

World Map Builder comes from developer Seve Savoie Teruel, and delivers exactly what it proposes. Through a simple drag-and-drop interface, designers create their own map, stylized after Super Mario Bros. 3, and effortlessly guide players from one level to the next.

OK, maybe “effortlessly” is a little hyperbolic. Because World Map Builder has to work within the constraints Nintendo has placed on Mario Maker—it’s not like Nintendo has a public set of tools or APIs for people to play with—Teruel was forced to get creative to make this work.

Because it exists outside Mario Maker, which means “finishing” a stage won’t push you towards the next stage in the game itself, World Map Builder came up with another way to gate progress. At the end of a stage, designers place an “exit code” made up four items: donut block, note block, fire flower, key. The order of the items is important, because when a player then punches them into a map, it “unlocks” the next stage and reveals the level code.

The map is accessed via web browser, and works fine on phones, too.

Teruel told me he doesn’t have an “endgame” for World Map Builder because people keep suggesting new ideas. (For example, it’s now possible to track lives from stage-to-stage.)

World maps in Mario games are functionally similar to playlists. You can take players on a curated journey, where ideas and themes naturally, rhythmically build on one another over the course of a world. Mario Maker 2 offers neither to designers, to the game’s detriment.

You’ll also notice World Map Builder, despite including sprites that very much look like they came from Super Mario Bros 3., absolutely does not feature any sprites ripped from Super Mario Bros. 3. This is on purpose; Nintendo is notorious for shutting down public-facing fan projects, and Teruel hopes the lack of official sprites means he’ll avoid their legal wrath.

“It's a useless site without Mario Maker,” said Teruel, “so it’s a symbiotic relationship that only benefits Nintendo. But it's Nintendo.”

It is possible to add custom sprites to World Map Builder, however. So... you know.

In any case, for the moment, World Map Builder lives. In a just world, Nintendo would let this quietly live, take some notes, and put something better into Mario Maker 2. But more than likely, this remains a cool, niche thing that gestures at an even better Mario Maker we’ll never play.