Mario Kart Live: Revisiting a Sleeper Hit

On October 16th, 2020, in the midst of a global shutdown, Nintendo launched what is arguably one of the coolest accessories ever for the Nintendo Switch. Imagine what it would be like to play Mario Kart on your Switch in augmented reality.

Welcome to Mario Kart Live: Home Circuit.

Available for a cool $99, the RC car you could control with your Switch and actually race with allowed you to see through the eyes of Mario or Luigi, create your own courses, and do real multiplayer racing (up to four players!) on ground you control. It’s an incredible experience, and honestly a ton of fun. The way that it works is brilliant. Each kart has a camera, and the kart streams video over a local LAN connection back to the console. The game can do basic image recognition on a handful of pre-defined textures, like the arrows of the direction signs and the four gates that are used to build the courses. Thankfully, they’re also fairly lenient in what they recognize, making it easy to build third party accessories that work well.

Unfortunately, this incredible toy was not long for this world. After only a few years, Nintendo slowly and quietly began to phase out production of Mario Kart Live. It was a decent seller – 1.73 million units as of December 2022 – but not a great seller. Serious issues weighed it down:

• At $99 per kart, and (at launch) requiring a Switch per player, startup costs are $400 ($299 switch, $99 kart) per player
  • Software v2.0 allows for split-screen multiplayer, so if you’re willing to play on the TV, you can get the price down to $500 per two players
• It’s up to four player multiplayer… with only two karts released

It’s reasonable to assume that Nintendo planned to eventually release additional characters (version 2.0’s Relay Mode features Peach, Toad, and Yoshi as “playable” characters, but only in Relay Mode), but these karts never materialized. Instead, consumers were left with a choice:

If I have four people who want to play, how do we keep track of who’s who when we’ve got two Marios and two Luigis driving around?

At Riley Children’s Hospital, we have seven karts total, with six in regular use. Four Marios and three Luigis. I don’t know about you, but that doesn’t sound very fun. Over the past year, I’ve been disassembling, reassembling, and modding these karts to make something truly different — and finally, after many prototypes, a lot of paint, and at least a little swearing, I’m happy to announce that if you have more than a handful of these little things, you can now theme them with a 3D printer, a little elbow grease, and some paint. My partner (major shoutouts for her help and work with painting!!!!) and I have themed four of them so far, with each one getting more advanced.

As of today, I’m releasing the following:

• a replacement seat that you can model your own character for
• replacement 3D-printable pieces for each of the colored parts on a Kart

Notably, what I’m not including are the characters themselves due to intellectual property concerns. Instead, I will point you to Spriter’s Resource, a site that hosts models and sprites obtained from the assets of different older games. The models aren’t very easy to work with, but their selection is excellent, so you’ll likely be able to find any character you’re looking for.

The parts themselves are not an easy print; all of them require supports (and sometimes different materials; I used PLA & PETG for Toad, but the gray booster arms need to be TPU so that they don’t break as easily) and are sometimes quite fiddly. If I’ve learned one thing, it’s that reverse-engineering injection molds is not tremendously fun.

Dozens of prototypes later, I hope that my work helps you build something genuinely cool. You can find the parts on Printables for free – I just ask that you upload a make so I can see what you’ve made when you’re done!

It’s hard to communicate in words how overjoyed a child can be when they learn they can drive as their favorite character – or literally anyone other than the plumber brothers. I’m very proud of the work that we’ve done, and I hope that you can use this as a jumping-off point to use these fantastic toys to bring joy.

Best of luck!