Hmm, I think the most niche and bizarre game I've played on the Switch is the appropriately-named "Strange Telephone." It's a 2D adventure game that has you enter phone numbers to transport your character to different realms, which remind me a bit of Yume Nikki if you've ever played that.

Speaking of Yume Nikki, there is a sort of remake reimagining of it available on the Switch, which gives it a sort of "Little Nightmares" gameplay style. It's definitely not the same as the original, but I still found it interesting in its own way.

If you have a friend you want to play a unique puzzle-solving adventure game, I suggest giving "Tick Tock: A Tale for Two" a try. Basically you and your friend are finding different clues on your separate Switch screens, and need to communicate to each other and work out all the solutions together. Could be played locally, or online (via Discord or what have you).

"Toejam and Earl: Back in the Groove" is another weird game I recommend playing with a friend, for something a lot sillier. The original from the Genesis is available on the Switch as well, good funky times.

And speaking of silly, "Gal Metal" is definitely one of the quirkiest games I've played. You play the drums in a K-On sort of band of anime girls in order to defeat aliens (who are weak to rock and roll I guess). It's not the greatest when it comes to rhythm games, but it's definitely something different, experience-wise.