No worries. I wouldn't have realized it either if I didn't work retail during the Wii craze. 

None of these underperformed. Wtf?

Yoshi's Crafted World - 3.01mil as of December 2021

It's one of the best selling Yoshi games and has had pretty good legs.

Astral Chain - 1.28mil as of December 2021

It didn't have good legs but the developers were surprised by how well it sold before it even hit 1mil. It broke even very quickly and outperformed expectations.

Captain Toad - 2.13mil as of December 2021

How is that an underperformance? Seriously.

Miitopia - 1.68mil as of March 2022

It quickly outsold the 3DS original and for being pretty mediocre and having barely any gameplay it sold pretty well.

Not everything needs to be a massive seller to not be an underperformance.

Might as well list another dozen games here.

WarioWare and Pokémon Mystery Dungeon maybe underformed.

Idk I feel like "underperformed" is a word used when expectation isn't met. For example it's a lot worse for a mainline Mario game to sell just a million compared to something like Astral Chain selling a million. A new IP selling a million is really good especially if it isn't AAA with a huge budget. So there really aren't many Nintendo published games that underperformed on the Switch expect for maybe something like Sushi Striker. However, I do think there were games that could have done better, deserves better, etc.

Games that could have done better imo:
Super Mario Maker 2
Nintendo Labo
Pokken
Pokemon Snap
Mario + Rabbids
Bayonetta 3
Xenoblade 3
and maybe 1-2 switch although I think it overperformed for what it is

Deserves better:
Metroid Dread
Astral Chain
Pikmin series

Overperformed:
Clubhouse Games (lol)

Honestly I’m mostly surprised Skyward Sword at this point has done the same numbers as it did on the Wii. Would’ve expected at least 7m by now.

I think Xenoblade 3 would’ve been higher by now but it’s still outselling Xeno 2 at this rate and I do believe with legs it will hit 3m. I mean heck Three Houses is at 4m and that was the number I wished for when it first came out.

The hardest games to predict sales are ones targeted towards casuals and non-gamers so I wouldn't count them as underperformed or overperformed. Those are hits and misses.
Like Kawashima's Brain training (Brain age) although the DS version passed 10m, Brain academy, Game Builder Garage, Clubhouse games, Fitness boxing, Ring fit, Switch sports, etc.

I agree on Mario Maker, it seems like a game anyone that pay's for online access on Switch online should have. I think Nintendo's never drop their first party games lower than $39.99 on sales and below $29.99 on black Friday hurts sales after they hit their saturation point. There are plenty of Playstation games that I buy at $19.99 or less, and I probably would bite on some of these games like Mario Tennis, Mario Golf, Mario Party if I saw them at $19.99 or less, but they just aren't games I need to buy.

I was never bound to happen. Persona breaktrough was due to a combination of gameplay focusing heavily on social sim mechanics, presentation (overall distinct and very memorable aesthetics) and a very high school anime-like setting of story/characters

I didn't play Xeno 3, but the trailers gave me the impression it was pretty much Xeno 1 in new clothes. If the Xeno 1 was not a major seller, there was few reasons to believe Xeno 3 would be a major seller either. Even if the game in the end was significantly different, an average person like would hardly know it because it wasn't marketed as such. 

My impression playing Xeno 1 is that a RPG that is competent, but lacks something to stand out as unique, something other games don't have. For instance, team Asano games have their HD-2D, Fire Emblem have its permadeath, Dragon Quest have their Dragon Ball artstyle, Kingdom Hearts have the Disney characters, and the list goes on

I can't remember a single thing from Xenoblade1 that makes me think "This is so Xenoblade". If Monolith somehow manage to bring something that is easy to market and can be easily perceived as a must play then the franchise can finally have its breaktrough 

I also think Pokemkn Snap underperformed, I was expecting 5 million

But again, I was hyped for the game I didn't buy it anyway. The price tag was asking way too much for this kind of game that doesn't have that much content to offer

The reviews were also pretty mixed for both critics and fans, so I given up

I'm sure Nintendo is dissapointed sith Skyward Sword. It was marketed almost as a new game  compared it to Metroid Prime Remaster launch and you will understand what I mean. That's said, the sales did not surprised me

The game got much worse reviews in retrospect than at launch, pretty much confirming the initial reception of the game was only due to Zelda prestige rather than the quality of the game itself. With middling reviews and lukewarm public reception, close to no enhancements compared to the original and asking 60 USD for a game that have no affective memory from gamers I'm actually surprised it managed to sell 3 million because it clearly don't deserved it. 

These sales for Pokemon Snap and Origami King are great actually. Not every entry needs to do 10 millions to be a success.
Mario Maker 2 and Mario Strikers were underwhelming compared to their sale potential.
Paper Mario and Pokemon snap were still pretty niche.

Snap sold 3,6 million in the tinny N64 userbase, the 11th best selling game in the platform. Not niche by any means and was a clear potential 10 million seller if the game was better