Some of the images and videos shown in text were created during development.

This article has been translated from the original Japanese content.

Yabuki-san first brought it up around 2020. Back then, we already had an idea of the next console's expected specs, but it wasn't until a bit later that we actually received working development units. Until then, we just had to proceed with development based on provisional estimates.

When we were developing for Nintendo Switch, we often worried whether we could find the right balance between planning and performance. Of course, the Switch console's performance is sufficient for developing different kinds of games, but if we had included everything we wanted to in this game's vast world, then it wouldn't have run at 60 fps and would have suffered from constant framerate drops. I think there were a lot of people on the team who were worried about whether we could really manage it. But once we decided to release this game on Switch 2, we expected our worries to evaporate all at once. I remember being overjoyed when I discovered we could express even more than we'd originally set out to.

That's right. Of course, the graphics needed to be more detailed. But like Sato-san, I also felt like it was outweighed by the sense of relief. From the beginning, the designers were saying they wanted to make the art richer, so I thought we could achieve that now. For example, team members who were creating the terrain in the scenery were really happy because they could now place more trees, which were key to giving the world a more natural look.

Jikumaru-san drew up a rough map for us to start discussing where to place them. We first placed the existing courses in the world based on the directions of the compass and created a setting for them. For example, the climate gets drier as you go west, so we thought we could place the Shy Guy Bazaar course from previous games with its palace in this area, and perhaps place the Desert Hills course nearby. Going northeast, we thought we could make this region colder with a steep, snowy mountain as a landmark, and have a course where you can race at its peak. When designing courses based on the climate, we also tried to be creative so that the routes that connect courses are seamless and that the scenery around you changes before you know it.

Each individual course has its own distinct characteristics, so connecting them all was pretty tricky. We had to place existing courses in a way that fits the context of the world without losing what makes them special.

I recall the team lead for terrain telling us that we need to keep context in mind. Each course was built around its own unique and distinctive concept, so if the landscape between the courses was barren, then it would feel like the world was just divided into chunks. That’s why it's important to establish a context that connects them in a way that feels natural while making use of contrast to create surprises. For example, we thought it would be good if, from Mario Bros. Circuit, you could keep driving down a wide road like Route 66 (6). The scenery would gradually thin out, while up ahead you'd see a landmark that resembles Monument Valley, and the road would ultimately connect to a big city.

Footage captured while in development

We wanted players to experience being in the next area before they knew it, so we had to work out where to put impactful changes in scenery like landmarks so that we could realise that while still making it seamless.

(6) A former national highway spanning the United States. It runs from Chicago, Illinois, in the Midwest to Santa Monica, California, in the Southwest and passes through all kinds of landmarks, such as national parks and deserts.

First we created music for the courses like we've always done before and then thought about what to do for the roads outside the courses. We decided to have two different kinds of music depending on how you're playing. For the Knockout Tour mode, we started off by simply trying to connect the course themes. But that approach didn't work well. It ended up sounding weird because the tracks have different tempos and beats. So we decided to find a way to end each of the course themes, even though they're connected by the route. Video game music often plays on a loop, and in this game too, the same music keeps playing if you're driving laps around a course. But for Knockout Tour, as you get closer to the next course, the music transitions to the outro, so the theme ends nicely. We also created a new intro for each course theme which starts to play shortly before you reach the gate, building excitement. Then, as you actually pass through the gate, it changes to the theme of the course you've entered. By repeating this, it feels like a medley is playing along to you live, creating a sense of immersion.

For other modes like Free Roam, we prepared lots of music in addition to course themes and made it so the game would automatically select the right track depending on the situation. During development, we called this the "jukebox". For this, we created lots of arrangements of music composed for past Super Mario and Mario Kart games.

Altogether, over 200 for the "jukebox". These are all brand-new arrangements, and we also did live recordings. We prepared pieces from quite a wide variety of musical genres. I believe those who are well-versed in video game music, as well as those who aren't, will enjoy listening to them.

Exactly. Whenever designers get the chance to create such a vast world, they tend to become bold and adventurous, fully aware that it means a much higher volume of content that they need to work on. What if we could make the scenery in this interconnected world change with the time of day… What if we could create a world that looks as if people actually live there… We thought this would be so nice and make the game so full of emotion, that it led to the creation of sketches like these.

But we spent a long time discussing within the team whether we could really implement time and weather changes.

Right, the sheer volume of work required to prepare all the art needed to show time and weather changes in a seamless world... We were under no illusion. (Laughs) We were even on the verge of giving up on it at one point.

But the appeal of having time and weather changes won out. So we decided to try and find a way to implement this feature that we'd initially considered giving up.

Also, in terms of course design, if the time of day and weather are fixed, then it's easier to create the clearest path under those conditions. But even just with changes in brightness or the angle of the light, we have to check multiple variations and adjust them accordingly. In that sense, everyone was happy that they could achieve more things, but I'm sure they also ran into a lot of difficulties when it came to actually making it.

Yup, it was even worse than we imagined. (Laughs) But the graphics programmers were also determined to create something good and worked ambitiously to make it happen, rallying support from various people.

The programmers were also worried about how they were going to work together to handle this volume of content. We knew what we wanted to do, but the big challenge was working out how we could actually complete it. That said, we thought it might be possible if we could change our development approach in a way that reduces the workload.

We designed it so that a day in the game passes in around 24 minutes. You easily get a sense of how time passes in the game, since it happens faster than in real life. But the time doesn't progress evenly, does it?

At first, we made the colour of the sky gradually change over time, but in many cases, we considered the time and scenery together. For example, we wanted players to be able to experience the desert at night. In this case, when there's a particular scene we really want players to see, we didn't think such a feature would work, as players might drive through that location at the rather bland time between evening and night. So I discussed this issue with the programmers, and we decided to focus on the most appealing times of day and dramatically shorten the transitions between day and night.

Rather than having the time change in accordance with the real world, we prioritised it working well with the gameplay. Besides that, in terms of weather changes, sometimes it will rain or snow, or there might be a flash from the Lightning power-up followed by a sudden change in weather. For these kinds of things as well, we were thinking about how we could make a lasting impression on players and what kinds of effects would be fun for them as they drive around. For the background music, we took songs from a variety of previous Super Mario games and arranged them into fun driving tunes, which I think will add an extra layer of enjoyment for players.

The "jukebox" feature will have you racing towards Bowser's Castle while listening to Bowser's Road from Super Mario 64 (7) or going for a nighttime spin while soaking in the Rainbow Road theme from Super Mario Kart. During the daytime, various bright and cheerful tracks play. In the evening and at night, the arrangements are more chilled. We recorded a band arrangement for the Staff Credits theme from Mario Kart DS in a style that fits this new game, and I personally was really moved when I listened to it driving around during the game's evening scenes. You can enjoy it even without knowing the original tracks, but I think someone with fond memories of playing various Super Mario games will feel a wave of nostalgia listening to these tunes as they drive around.

(7) Super Mario 64, a Nintendo 64 launch title released in March 1997 in Europe. It is the first full 3D platforming game in the Super Mario series. In this game, players can freely run and explore in a 3D space using the control stick.

Mario Kart is a series of racing games that has placed a lot of emphasis on "drifting" over the years, so the courses were designed with lots of bends. But in this game, since you're driving around an interconnected world, we needed to make it fun to drive not only around corners, but also in a straight line.

For example, when going from point A to point B, we tried placing lots of bends along the way like we always do. But with too many bends, you lose sight of your destination. Then your goal of travelling from point A to point B becomes more difficult. That said, driving for ages down a straight road isn't much fun either. So we figured what we were lacking was some kind of gameplay mechanic for straight roads, and that's where the idea for some of the game's new elements, such as Rail Ride and Wall Ride, came from. The development team collectively referred to these new features as "tricks".

If everywhere's just straight roads, it's going to feel the same no matter where you drive.

With such a vast world, we thought it'd be a shame if you were just driving in a straight line the whole time. Then, we found a hint from a book that said, "Skateboards create infinite possibilities in a city with just a single piece of wood”. Tricks can open up a multitude of driving possibilities for just a single wall or dirt track. We thought it would be fun to be able to drive in completely different ways just based on the player's imagination, so we made the gameplay more varied. For tricks like Rail Ride and the Wall Ride, we referenced extreme sports like skateboarding, snowboarding, and BMX.

I think these tricks will really give players a chance to use their imagination as they come up with ideas like "I'm gonna drive up that wall", "Let me use that pillar", or "Can I ride that guard rail or power line?".

In this game, you don't just race on the courses. The areas between courses are also used for racing. So it's as if there are courses spread out all over the world, and if you were to add up all the possible variations, it would easily exceed 100.

(Laughs)

Yabuki:
Since it's now a single, interconnected world, it's hard to do a direct comparison with the last game, but in the pursuit of approachability and fun in this new, vast world, the volume of content we had to create in terms of visual design, programming, and audio increased dramatically. And as a result, the gameplay is more varied than ever before.

Continue to Chapter 3: An interconnected world