For mine, I have three fundamental rules;
1.) In this hypothetical game, there would be updates after the initial release to add more characters to please more fans
2.) There will be third parties included, with a total of two in the base 12 roster
3.) In the base roster of 12, there will only be one character per series represented as to allow as many different characters to be represented as possible.
With that being said, here’s the 8 starter characters and their explanations/stages:

- The face of Nintendo, no explanation needed. Stage: Mushroom Kingdom

- Huge Nintendo character, no-brainer. Stage: Jungle Hijinx

- Zelda is one of the most revered series in the world, obviously he’s here. Stage: Great Plateau Tower

- Metroid is huge, another no-brainer imo. Stage: Brinstar

- Sakurai’s baby, even if Sakurai doesn’t direct this hypothetical game I feel it’d be disrespectful not to include him, plus he’s a huge icon. Stage: Green Greens

- Pokemon is debatably the biggest media franchise on earth, there’s no possible way he’d EVER not be in smash. Stage: Pokemon Stadium

- Although StarFox isn’t quite as popular as it once was, Fox is still an icon with a ton of smash history, it’d be wrong in my eyes to exclude him. Stage: Corneria

- The last starter character, Splatoon is possibly the biggest Nintendo IP to crop up in the last decade, Inkling absolutely deserves their spot. Stage: Moray Towers
Now for the 4 unlockable characters and their explanations/stages:

- Animal Crossing is a massive series, so they definitely deserve a character. Between Villager and Isabelle, I went with Isabelle who, despite not being the ‘main protagonist’ like Villager, is the overall more popular character and represents the series better imo. Stage: Town and City

- For the last first party slot, it was a tough decision between Marth, Olimar, Pit, and Shulk, but I ultimately went with Marth due to FE being the biggest series of the group and for having a rich Smash history. Stage: Castle Siege

- The first third party slot has got to go to Sonic if you ask me, he’s wildly iconic and his company’s history with Nintendo is such a big part of gaming history that he’s earned the spot. Stage: Green Hill Zone
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- The final slot... it was a super difficult decision between the remaining third parties, but I ended up with Pacman due to him being one of the most iconic figures not only in gaming, but in media as a whole; it’s undeniable he’s earned his spot. Stage: Pac-Maze
Thoughts on my choices? Share them, I’d love to hear them!