Mario is Missing! was shaped by a Carmen Sandiego rivalry and miscommunication

Generally when it comes to Mario games, Mario is the star of his own world. But that shifted in 1993 with Mario is Missing!, a title that broke the series' traditional formula by focusing on exploration over platforming, starring Luigi as he attempted to find his kidnapped brother."

Mario is Missing! was part of a line of educational (or "edutainment") games, several of which were made by Software Toolworks. In a recent retrospective from Time Extension, the studio's lead designer Donald W. Laabs revealed how a rivalry with another famous series played a surprising role in the game's development. 

While Nintendo left the studio to its own devices, Laabs speculated the publisher may not have known what it was getting into during development. He understood that Nintendo clearly wanted an edutainment game, but felt that it hadn't "fully realized what the [Nintendo of America] deal committed the company to."

Even so, the staff was said to be "honored" to make Mario is Missing!. Several staffers like MS-DOS programmer Jeff Chasen, were fans of the series, and said they looked back to the original games often for inspiration. 

Since Toolworks was the first non-Nintendo studio to ever make a Mario game, giving Missing! a distinct identity from the main series was important. According to Laabs, the studio's lead artist had to go to 'Mario art school' to learn how to properly convey the series' characters.

One other way to make the game's spinoff status clear? Molding it after the dominant edutainment franchise at the time. 

Mario wanted to find Carmen Sandiego and take her crown

Speaking plainly to Time Extension, Laabs admits Missing! was meant to compete with Broderbund's long-running Carmen Sandiego series. "It was thought that a licensed character like Mario would carry a lot of weight." 

Part of that involved bringing on designers from the rival edutainment series onto the Missing! team. It's clear through the game's design and interface what it's aping from, though that move wasn't encouraged by everyone at Toolworks back then. 

"There was a lot of push-pull between company factions," acknowledged Chasen. "We did spend a lot of time looking at Carmen San Diego and its design and trying to balance that out with what we knew about Mario." 

In the end, it paid off. Mario is Missing! generated a reported $7 million in revenue for Software Toolworks, and birthed more edutainment Mario titles such as Mario's Time Machine and the Mario's Early Years sub-series. 

And at large, you can see how the game went to shape future Mario titles, both mainline entries and spinoffs. This marks Luigi's first starring role in a video game, making this a precursor to the Luigi's Mansion series. It also led to other third-party studios getting to tackle Mario, like Ubisoft with the Mario+Rabbids games. 

You can read Time Extension's retrospective for a deeper look into Mario is Missing!, including a deeper look at its impact post-launch and Software Toolworks' thoughts on getting to develop a franchise much of its staff grew up with.