Knockout City

Note: This game is known to be glitchy with its achievements. If it doesn't unlock for you when doing this, you'll have to reboot your game and try again. Even then, it may not work. I had to do this for several achievements to unlock.

Note 2: This game type can definitely disappear and be replaced with a different game type at any point. The 1v1 Faceoff mode that was here at launch has been removed. If this game type happens to disappear, you'll have to wait for the map to come around normally with the Moon Ball to get this.

Note 3: According to REV X SHADOWS in the comments, this achievement will actually unlock by using the pad next to the stage and flying across. You don't have to stand on the stage at all which means another person or the Moon Ball is not needed.

I did this solo in the Party Team KO game mode, but in can be done in the normal Team KO mode as well, as long as you get the Moon Ball on this map. In the Party Team KO mode, all of the balls are special balls. They can be one type the whole match or you can get it when all balls are in play. That is when I get this achievement.

In the video below (you won't see the achievement unlock due to the Xbox recording), you'll see I waited until I grabbed a Moon Ball and then I head over to the Bandstand. From here, I took a running start and jumped and started gliding diagonally across the buildings, over the gap. When you hit the updraft, you'll get a tiny little boost up that will prevent you from hitting the bridge in the middle. Once you make it to about the middle of the Gardens area, the achievement will unlock. Fairly easy achievement once you actually get the map and the right ball.

Alternatively, you could have someone throw you across the gap if you don't want to play against the RNG in this game. This solution was mainly for solo players though.

So like some others said, this is a bit glitchy, but here is how I got it to work

So this is extremely glitchy I got it literally just gliding from the garage area to the gardens I wasn’t even near the bandstand and it popped for me. So if you can’t get it try doing it like I did maybe it’ll pop.