because wii u would have to sell 25m first before it can sell 25m gta games? because not every nba fan will buy a wii u then and will stick with his nba game on a playstation? because a game like borderlands sells a lot of units on pc and i don't really believe nintendo would be also a pc developer?

Fair enough criteria, but I have a few things to add:

1. Brawl would be a more fitting representation than Melee if only because it is a more recent example of the direction Nintendo has been taking with its franchises. I also believe that the use of color in Melee was an attempt to uniformalize the art direction more than anything else, as certain characters do seem to look quite different from their portrayals in their native franchise. Brawl's characters are more faithfully depicted (though there are exceptions, like Toon Link, interestingly).

2. Also take into account the Japanese perspective. Some of Nintendo's more anime-esque franchises feature brightly colored characters, but are actually geared to teens and adults. Namely Fire Emblem, where a distinction could possibly be made for how the actual in-game models (or sprites), as well as the environments, are designed compared to the character portraits. This also seems to hold true for parts of the world impacted by Japanese popular culture, in my experience.

3. Taking this further, it's not hard to see how many Nintendo franchises are influenced by specific styles of anime as well as western animation. F-Zero leans towards what appears to be a cross between comic book and sci-fi teen/adult anime (and indeed there was a surprisingly mature F-Zero anime). I think there's plenty of room to go deeper into this topic beyond using primary colors.

Fire Emblem isnt geared towards adults its accessible to adults in japan, but that doesnt speak for the world none of their games are. Those games are aimed at teenagers.

Most Fire Emblem games are rated everyone, but there are a couple that were marked for the specific demographic of teenagers.

Fzero might have had an anime but I've never seen it. I am sure it was accessible to adults, in Japan. 

Brawl is definitely aimed at children to teenagers (moreso teenagers today). It started out as a game for everyone but after the cube the color schemes changed and got darker and everything got a tad deeper. With Namco at the helm its definitely going to stick with the teen crowd its been focused on as of late.

Look at the use of light and shadow, mixtures of tones aand textures and the duller colors? They are definitely moving in a different art direction with this game.

I don't think Nintendo could afford Take-Two. At the very least they are probably worth over 1 billion dollars

http://en.wikipedia.org/wiki/F-Zero:_GP_Legend_(anime)#Anime

The F-Zero anime had a short-lived run in North America, and was apparently "modified" by 4kids (I take that as censorship). F-Zero GX's Story Mode had some darker moments to it, but nothing particularly substantial. Entreched in the teen demographic for sure.

Of the six Fire Emblem games released worldwide, only the two GBA games are E-rated, with one E10-rated and three T-rated. All signs point to the series sticking with a primarily teen audience outside of Japan, while in Japan it has become a mainstream RPG franchise.

It'll be interesing to see how the new SSB turns out. Most likely taking an aim at teens again, I'd imagine.

All is well and good, though. Teens are very prominent consumers of entertainment, to say the least.

I don't think Nintendo could afford Take-Two. At the very least they are probably worth over 1 billion dollars

I never said teens werent a good demographic, they really are but my point is Nintendos wheelhouse demographics are children to teenagers. My point is adults are gained by association and product value, but Nintendo is aiming to children and teenagers by the way they package their products. The Wii was a different turn where they commercialized themselves as the family box to bring the family together. When it comes to mature games on Nintendo Nintendo always lets other people do that work for them. They dont like to do it themselves, hence why Rare made such an impact with their creativity and their in your face style and even sometimes took the stoplight from Nintendo themselves. Led to problems between them and Nintendo in the end but you get the picture.