This is one of my favorite Nintendo Switch games of all time, and it's the Switch game I've played the most as of now. I'd have to agree with what a couple of the other reviews say: this is a piece of Nintendo nostalgia! There is a wide variety of different Nintendo characters to play as: Mario, Luigi, Bowser, Bowser Jr, Yoshi, Link, Villager, Tom Nook, Toad, Donkey Kong, Princess Peach, and many more. There's a lot of fast paced and catchy music that plays when the races go on, and it sounds similar to music from old video games and makes the game more fun to play!
There are a lot of unique locations to race at, like Cheese Land, Baby Park, City Tracks, Animal Crossing, and many more. Each of the locations have a specific theme, sometimes ones related to aspects of the other games that the characters are from, like babies, music, trains, rainbows, sweet foods, mushrooms, Yoshi's Island, and more, which gives the game uniqueness, a lot of detail, and huge combinations of the characters' franchises! They're all so bright and colorful, especially Rainbow Road. There's one location looks a lot like Andy's room from Toy Story, but I can't think of the name of it.
I didn't know this until I searched up this game on here, but this and Mario Kart 8 are 2 different games. I read in another review that this is an expanded version of Mario Kart 8. I like the sound of that!