Retro Studios has been a subsidiary of Nintendo since 2000. They are the only overseas first-party developer for Nintendo. And everything else you listed is second-party... Nintendo oversees (or oversaw, in the case of released games), the development of those games.
Satoru Iwata was a genius that helped shape a lot of my childhood... and he saw Nintendo though some of its best times since the original NES and some of its worst times too as CEO... but Nintendo has done more good for the industry than it has bad, even in recent years and nothing represents this better than this quote from Iwata:
"Video games are meant to be just one thing. Fun. Fun for everyone."
Nintendo games may not be epic in scale. They may not be graphically impressive. They may not even have deep stories. But above everything else, they are fun.
Why do I want a final mouse? My current mouse is a 3 button, Insignia mouse... it doesnt do anything special... click, right click, scroll and middle click and thats it. I could really using a gaming mouse.
Getting this processor would allow me to put together an awesome gaming rig (and my first built PC) and be able to better spend my available funds on components other than the processor, like a better GFX card or an ssd.