Even though you mean the Metal Gear(MSX2)
(Solid) debut on a Nintendo console in Twin Snakes, which was a remake of the original Metal Gear Solid.
were obvious to join Smash one way or another. Sonic was Mario's enemy turned friend. When Sega had nowhere to go, Nintendo took them(sorta) like they were Shredder and Sega was Karai. Pacman has had most of his console games on Nintendo. Add that with the fact Namco made MarioKart Arcade(both of them), and is currently working on Pokken while Nintendo made a Pacman game themselves, nest friends(also one of the few companies from the 80s that are still awesome).
is a Nintendo character. That is all...
even though his best game was on a Nintendo system, they didn't really like fighting games, especially if it involved Melee, up until Smash 4. Fortunately it helps that Ryu is the fightinggame king, and only fits on Arcades, Nintendo and Playstation systems. Something abut Street Fighter on Xbox is for some reason weird.
Shantae out of every single indie star in the world, has a bigger chance in getting into Smash than Chrom and Knuckles do.