I'm wondering what hidden gems you have stashed in your hoard. I limited myself to Switch because I happen to have my menu open on my Switch atm, but you can mention games for any console or for PC (though it'd be nice if they are games that are playable without searching out a console that is no longer on the market, otherwise you're just torturing us with games we can never play.)
What games have you played that have had low exposure? People call these games 'underrated', though that word is often being used wrongly. For example, one guy insisted to me that Astral Chain was an 'underrated' game, and I wanted to know what the sweet vanilla fudge he meant when it is, by EVERY metric, rated incredibly highly, scoring 9.8 and 9.9 on basically every scale in existence. But later, I realized that he was probably trying to say that it is UNDEREXPOSED, under-marketed, or under-played, under-realized...hard to decide the best word, but: meaning that it's more obscure and lesser-known than it deserves to be. It's NOT underrated because it has very, very high ratings, but so few people have ever played it, compared to, well...Pokemon or ACNH. Even Xenoblade has more players than Astral Chain, and Xenoblade is also an under-played series even with the increase it's seen since the first game. It's not a game that should only be selling 1-2 million compared to games like Pokemon, Smash and AC. But I guess story-heavy, weighty games like Xenoblade will never be as popular as lighter, faster, more easily-consumed fare.
These games are the hidden gems of the gaming world. And here on Fogu, we're niche-game experts. Our favourite genre has finally seen a boom (though it may be a trend that fades away...we happen to be at the right time past the monstrous success of Stardew for current and upcoming copy-cats and inspired-bys to be saturating the market, right now.) but even with that, it's still pretty niche...everyone has heard of the genre, now, but most of them still haven't actually tried it.
I don't have any requirements for what you consider to be a 'hidden gem' game. It doesn't have to be indie. It doesn't have to have a certain price point. I think the only requirement is that the game SURPRISED you with how good it was, for some reason, and made you wonder why it isn't better known/more popular/more talked about. Or maybe you're a smartypants and can figure out why, but you still think it SHOULD be played by more people.

For me...
This one will be boring here, because most people have probably already played it...Fogu being that kind of a place, and all.

Hope's Farm really surprised me with how much I enjoyed it. I played it like a maniac. That may come down to me never having realized that Match-3 games are like drugs for me, to the point of being an effective painkiller when dealing with chronic pain and discomfort. But it's also a game that costs $2 when it is NOT on sale, and I got it on sale, so it cost something like $0.39. And it's farm-themed! Extra nice if you're already a digital farming fan

Buried Stars, a VN, surprised me by coming out of nowhere. It's from...uhh...Korea? I think? It's actually localized pretty well...the translation makes sense, and the story (basically a murder mystery) and characters and gameplay mechanics are pretty interesting. There's no romance, in spite of it containing attractive teen/young adults of both genders.
Battle Chef Brigade was WAY more fun than I would have thought. It's...not EXACTLY a match-3. I mean, it sort of is, but...well, I don't know how to describe it, even in the puzzle part. It's kind of half way between tetris as match-3, maybe. And the gathering and fighting/platforming are pretty fun. The watercolour-esque graphics are really nice, too, and the story and characters are surprisingly kind of interesting? The cooking may have been the coolest part...it was so neat how there were so many dishes, and variations on each, depending on how you arranged the ingredients' components.
Final Fantasy XV POCKET EDITION blew me out of the water. I tried the original FF XV, and found it tiresome and borderline nonsensical, but the Pocket Edition was very punchy! It cut out every scrap of extraneous stuff and left just the surprisingly good story behind, to hit you right in the face with both barrels. My friend, who also was disappointed in the 'real' FFXV, loved the Pocket Edition SO MUCH that he went back and tried playing the original again, to try to dig even more out of the story...and gave up, lol. The original is so bloated and drawn out that it's like trying to enjoy your favourite drink a single drop at a time. It's too little to quench your thirst or even let you taste much of anything. Pocket Edition lets you take big gulps to consume it as fast as you want to, and it's delicious

Pikmin 3 surprised me because it was stressy, as you are under a time crunch and your little critters die very easily and make tragic noises when they do it...yet I still wanted to play. I wanted to find all that FRUIT. I wanted every fruit! It was surprisingly difficult to find and retrieve them all though, especially without losing too many Pikmin.
Jenny LeClue - Detectivu was...a throwback? I grew up on point-and-click adventure games. I played all the original Monkey Island games on PC, Torin's Passage, Day of the Tentacle, all the King's Quest games (6 was the very best), Quest for Glory (actually more of an early RPG, probably) Space Quest...etcetcetc. I played all of those when they first released, and LOVED most of them at the time. It's been quite a long time since I've actaully liked the genre, though...I got used to a different level of interaction and immersion when I switched from PC to console. But Jenny LeClue is the first point-and-click that won me over in 15 to 20 years. The story was interesting, and Jenny was good as the MC. I hope they do a sequel since the story was left hanging! Apparently one is in the works and has been for several years...the Twitter account is still active. I remember being surprised that I got invested, as I felt like this genre was just a thing that could no longer grab me, and generally that is TRUE...but Jenny LeClue managed it, somehow. I need to play it again. I will, when we know when the second one is coming. Jenny LeClue tends to be fairly affordable at the base price, and go on good sales, too.
It also has extensive voice acting, and it's got lots of flavour and isn't annoying.
Transistor is...well, it's by Supergiant (the folks who made Hades and Bastion) so it's not really a surprise that it's unique and has almost alarmingly charismatic characters. It's shorter than Bastion, and I love the art nouveau feeling it has. They do fantastic narrative voice.
Townscaper and Dorfromantik are both fun zone-out, time-waster games of artistic placement and design. Sometimes you can surprise yourself with how cool a thing you end up with, for a game that works on relatively simple placement and connection principles.
And I'll stop there.

So, what about you?