Mensrea on 15 June 2013
I don't think they really aim towards anyone specific, I think they try to make fun feature full games that are accessible, yet have more difficult aspects if you want that. There are a few exceptions though:
Metroid is clearly aimed at the older Nintendo gamer
Zelda is too, even at it's easiest, it's way to hard for a lot of kids.
Fire Emblem is for older Nintendo gamers
F-Zero is aimed at older Nintendo gamers.
I would argue that pikmin is aimed at older gamers
Frankly, I think almost every Nintendo franchise can be enjoyed even more by older gamers than children. Wii sports and other things like that are mostly what kids are able to play.
