Fair enough, but what happens if they act like the reat of the big-third party publishing industry, while releasing games that contain great gameplay?

Also a lot of people are saying "they should create/buy new IPs" but Nintendo has done this already countless times. Killer 7, Mad World, Eternal Darkness (which many consider one of the best horror games ever made), Geist, ZombiU, No more Heroes 1 AND 2, Conker's Bad Fur Day, Red Steel 1 & 2, even Resident Evil 4 was a GC exclusive for a while. ALL SOLD POORLY besides RE4 butRE games are already an established franchise and it sold mostly on the Wii than the GC. Hell, you can probably throw Bayonetta 2 in the mix since many here say it won't sell (I hope most of you are wrong ). Only reason why I suggest changing their existing ones is because it gives series the general audience are familiar with, while appealing to their existing fans, and a chance to draw out a new audience that THOUGHT this series were a certain way but turned out to be like something they like (Metroid looks like Destiny now? Awesome!)...

The family-friendly Gaming reputation is a double edge sword it seems.

Well, the game's sales and reception pretty much confirmed that it wasn't a good idea!

I mean, what exactly isn't mature about Metroid or many of the 3D Zeldas? Is it because Samus is a girl and not shooting Russians?

It needs the rating and you get that from blood, extreme action, and cursing. Pretty much what people seem to want.

Mario never. Or he'll end up with the hate of Shadow the Hedgehog. And it doesn't have to be Mario. It could be a new character. As long as you insert someone into a franchise, and they're hated, the franchise is fucked. There are things you shouldn't change. Unless you know for sure it's gonna get more people to buy the game. And not lose the existing fanbase. Case in point: Stargate Universe. They went too far, and got the franchise kicked to the curb.

As for your sugestions, NO. Don't mess with established series. The reason they are loved is because of what they do. Not what they don't do. Nintendo needs to invest in new franchises that are M rated. That's the only option. But still will take decades to erase that kiddy image. They need to make those games/series continuily. One off's, or 3rd party aren't gonna do it. If this worked. Then a fanbase is grown. Then 3rd partys have more options. And MIGHT actually put effort on their end, for a change. And not set stuff up to die.

The Prime Trilogy is as close to M as you can get without being there. They get to skirt the issue because blood is blue, aliens, no spoken words, and the game is colorful. But the lore is grimdark and depressing in every itteration, and at times just outright oppressive like on Bryo once you understand that those lizards you're killing were once a sentient race of magic-scientists. There's nothing EVER good about any of the places you visit... and that god-damned Valhalla level is straight out of a horror game.

If they made separate mature IPs then sure. But changing a current IP to be more mature is stupid.

They also need to show it. Reading horror stories doesn't cause a rating increase in a game. Just like how Pokemon gets by on certain ideas they imply. They don't show it, but you can assume horrible things are done from the enemy side. Don't tell me Team Rocket doesn't phsicaly abuse stolen Pokemon. To get then to listen. Or even certain Pokemon. Like Kyogre or Gourdon causing those hell storms near the end of Ruby/Sapp. People have got to been killed in the background. But since not shown, E. Or in a lot of TV shows. Take Power Rangers. No way no one dies during those giant fights. But not shown or mentioned, Y7.

Yeah, Samus gets a pass because the blood isn't red. Or the things she fights aren't human. Few easiet ways to avoid rating increases. But if she ripped heads off and deboned the aliens. That sure would trigger M. Even just having the sounds. Like if she slowly crushed a aliens head in. Hearing the alien cry mercy. While the camera just stayed on the wall. Or if it was a audio log of some kind. It needs to be visually or audioably there. And has to be on camera for a bit. You sneak by ratings if you cut fast. Like when Aragon cut heads off. Or when a Urukai smashed a goblin with that boulder. Really fast cuts. So you couldn't go "EWWW gross". Text, especially text that most people don't bother reading, free pass. Now if the text blocks were apart of the main game and were narated by someone. That could risk Metroid going into M land.

The original print run of Ocarina of Time on N64 had blood stains on the walls of the bottom of the well dungeon and had Ganon coughing up blood when he was defeated, although it was only for a split second. The problem apparently is that those games don't utilize a brown-and-grey color palette or have the main character swearing, they don't have blood and gibs spraying everywhere and don't have Link looking at naked elf girls before the game fades to black accompanied by a porn soundtrack of heavy breathing and the female character in the scene moaning loudly. Metroid doesn't have close-up shots of Samus's ass or crotch clad in panties that are obviously too small, like in the last part of Alien.

And yes, I know that the people complaining that Zelda isn't "mature" probably really want a Zelda that looks like a Skyrim or Dark Souls clone. But that isn't Zelda.

Again, if Nintendo decides they want to produce some M-rated games, as they did in the past with Perfect Dark or Eternal Darkness, they'll do it with all new properties, or perhaps with a revival of the latter franchise. Perhaps Nintendo could commission From Software to make a game for the Wii U in the vein of Dark Souls or Bloodborne, though I doubt it would sell a fraction of what Nintendo's bread-and-butter franchises do.

Most of the games you listed aren't actually Nintendo games...additionally, I would argue that many of them didn't sell poorly but that is another discussion

Let's narrow it down, shall we?

Killer7: 150k copies sold.

Eternal Darkness: 440k copies sold.

Geist: 150k copies sold.

ZombiU: 710K copies sold (not bad but this got a boost since it was a release title plus bundled in a console pack) so those numbers are somewhat misleading.

Red Steel: 660k copies (not bad again, but very diappointing because this was also a release title, and considering everyone and their mother literally were buying Wii's at the time, the fact this didn't break a Mill is mind boggling).

Red Steel 2: 600k copies (alright but nothing too special either).

Mad World: 740k copies ( not bad, I read on Wiki this sold a lot less, but I guess they didn't know what they were talking about. Still, this is not a number that jumps as anything special, especially since the Wii was in like 60mill + household's at the time.

No more Heroes: 540k copies (again a"meh")

No More Heroes 2: 380k (below a "meh")

Conker's Bad Fur Day: 770k (Not bad, considering it came out on the End of the N64's console cycle, only number that surprised me).

So you basically only proved Conker did great. Okay, maybe poorly is a bad choice of words, but all those sales are still disappointing, and they definitely played better than what they sold for.