Mario Kart is one of those games that I have played in about fourteen different versions, ever since I grabbed my first nintendo console. (Probably on a Gameboy, though might have been the N64.)
It's got even more tracks than usual, with 12 tournaments and 4 tracks per tournament. There's the usual mix of new tracks and revamped versions of old tracks (including three versions of the Rainbow Road - interestingly, these seemed rather easier than I remember from the Wii).
That's probably helped by the controller. The Joy Cons tend to drive me to play with the stick rather than motion control, being a little tricky to get a smooth movement when tilted. They do a rather neat trick of splitting in two to generate four controllers from two pairs though, which is dead handy when you generally only want to own two pairs of controllers.
The little split controllers are actually surprisingly effective, and I've thrashed the Girl an enjoyable amount of times with them.
Not yet got too deep into the battle mode, but have had considerable fun playing my way through the entire track set. There's not a bad course in them, though there's the usual incredibly annoying ones (looking at you, snow).
The progression through the game is a little different from normal, with all tracks being unlocked, with you instead winning additional vehicle pieces, either wheels, chassis or little parachutes. These have a significant effect on performance, as per usual, so make sure you build yourself something suitable if you're playing against someone who knows what they're doing.
Slightly excessive range of characters, which is nice.
It's also just massively fun. It's Mario Kart, what do you expect? Honestly, if you've got a Switch, you probably already own it.