I think it's more accurate to label titles and series as being niche. I'm not comfortable calling JRPG niche since Final Fantasy and Pokemon sale so much. Couldn't the argument be other JRPG just aren't as appealing as they should be to match Final Fantasy and Pokemon? Or that those two series simply dominate the JRPG genre so well, all attention to this genre is focused on these games.

Like Mario is a platformer. But who else really makes platformer besides Nintendo? And even then Mario massively outsales the other Nintendo platformers as well. Can we call platformer a niche genre when Mario can generally sale 10 million titles if userbase permits?

Part of it is appealing to the core base while being marketable.

Metroid never got a bigger push in America besides during the Prime 1/Fusion release window. I do think that a side scroller like many purist wish can't really sell so the series best hope is either a faithful 3D third person shooter or a FPS like the Prime series.

Metroid is just too hard of a concept to get into. It's slow, it's tedious at times, it's solitary. It's a great game, but it's not very mass market friendly. 

It's not much of a surprise that the "Metroid Prime" on GameCube or even with the red-hot Wii behind it, never really could fill the void that GoldenEye did on the N64 or do what Halo did for the XBox. 

I agree with all of this. But couldn't this be said about Dark Souls too? What is separating Metroid's potential to sale as well as the Dark Souls series? 

Nintendo hardware. The user base that Metroid appeals to are more likely to buy a PS or Xbox. And since Metroid would be one of a handful (generous) of games that appeal to that user base, sales are hamstrung.

At least that is what I think, but then again that doesn't explain Super Metroid. SNES was king and still Metroid didn't sell. Maybe it really is a Niche game and its about time we embraced its nicheness.

I really hope it isn't any of those two cases but it seems likely that it is or even both. It's just so weird because Nintendo fans are known for their weak affinty to shooters yet Nintendo was able to market Splatoon perfectly. Maybe because it was cartoony and that's why Federation Force was a multiplayer game that looked chibby? I'm just spitballing ideas at this point trying to find out this mystery.

Dark Souls is more about brutal action and challenge, with Gothic style. Metriod is more about exploration and isolation in a alien setting. The only thing comes close is No Man's Sky and that has massive hype behind it and pseudo galaxy explorations that no Metriod game could do while maintaining Metroid's map based interconnected charm level design.

To put it clearly a Metroid game that was 3rd person action game with customization and semi multiplayer like Dark Souls and other such games it probably would be the best selling in the series on a better selling console.

Yeah I was wrong to compare Metroid to Mario, FF, and GTA. 

So here's what I define as niche and it may be wrong as it seems to be a debatable term:

Niche:

1. It doesnt' sale over 1 million

Classic Niche:

1. History of decling sales

2. Sales were over 1 million in its first series, or reboot (like Metroid Prime high sale compared to the other two)

3. Decreasing brand awareness in the general market

This is hard to notice online for classic titles like Megaman, Castlevania, and Metroid, but these fans are either rare in real life or have been gaming for more than one generation

We should never compare Mario sales to GTA sales. Namely because holy crap NSMB DS and Wii did 30 million respectively a generation ago so its the userbase thats limiting these sales. And we should never compare a game to a game of a different genre. I should have never compared Metroid to Mario or GTA earlier. 

And I still think we can't call JRPG niche just because other games fail to be as relevant as FF and Pokemon or that the two simply outclass every JRPG there is in terms of mass market appeal. Just like Mario Kart is for Kart racer and Mario is for 2D and 3D platforming in this time period. Its like saying smartphone are niche because only Apple and Samsung consistenly dominate the industry. That's just wrong.

Sometimes there are genre that exist and just don't have a super popular title though. Like point click adventure games. This genre is niche and may never come back. But if it comes back in a big way somehow in smartphones, then we can't call this genre niche anymore. Just like we can't call puzzle games niche since Candy Crush, Bejeweled and Puzzles and Dragon are in this genre and dominate the smartphone gaming market. 

It sells low because of the skill it takes to play the game. You can't just pick up the original Metroid and beat it.

I wouldn't call a series that's consistently sold over a million units "niche" (only one of its mainline titles failed to sell a million copies), but its appeal is unfortunately somewhat limited by the amount of thought and skill it demands from its players.

As for comparing it to things like Dark Souls and Bioshock, the fact that it's exclusive to Nintendo consoles seems to completely explain why it doesn't sell as much as those titles on multiple platforms. Bloodborne, which pretty much is a Dark Souls game that is exclusive to a single console, has sold 2.3 million units, and that's on a much more popular console than Metroid usually is.