Cameos in Mario Kart World
Mario Kart World is still new. We are busy exploring it for hidden secrets and unlocking everything it has to offer.
Karts
Rally Romper
This default car is based on the Monster car from the NES racing game 3D Hot Rally.

R.O.B. H.O.G.
One of the unlockable bikes is based on the Famicom Robot (aka. Robotic Operating Buddy).

Mach Rocket
The jury is out on whether this bike is intended as a reference to the NES motorbike combat game Mach Rider, or if it simply shares a word in its name in common. There are some similarities, so it's included here for completion's sake.

Submitted by Fryguy64
D.K. Spaceport
The course D.K. Spaceport is modelled after the original arcade Donkey Kong. The rocket's service structure is made of slanting, red girders held together with tall ladder-like structures.

The course includes several callbacks to the original arcade game's sprites, including posters, oil cans and pictures of Fireball.



Game & Watch
The course also features callbacks to the Donkey Kong Game & Watch game.

The colour and Cross/Circle motif are based on the Game & Watch. Donkey Kong Game & Watch was the very first game to use a + shaped D-Pad.

A screen shows "sprites" of a barrel and girder taken from the Game & Watch Donkey Kong game.

An orange crane holds up part of the course using a steel cable. In the Game & Watch game, you would swing from a crane on a cable to clear each round.

Around the site are posters showing the evolution of Donkey Kong's rockets. They start with the Rocket Barrel from Donkey Kong Country Returns and end on the current model, named "Game & Watch".
Submitted by Fryguy64
Stickers
As you complete various tasks in the game, you will unlock stickers that you can apply to your vehicle. Many of these reference other Mario and Donkey Kong games, and some feature sprites from other games.
One of the stickers is gold and features the characters "GW-80". This is a reference to the Game & Watch. The first of these was released in 1980.

Submitted by Fryguy64