Anyway, on the subject of Nintendo crossovers and Subspace Emissary...Smash Bros. is obviously not going to do another big story like Subspace Emissary. So why don't people suggest a new Nintendo crossover game that tries to do what Subspace Emissary gave us? It may be hard to imagine a new Nintendo crossover game happening, but it's certainly not an impossibility.
I think I ask this because I once saw a thread in regards to people suggesting what take they would like to see a Nintendo crossover try and saw someone suggest something like Marvel Ultimate Alliance 3, where it's a singleplayer/Co-op experience with a team of Nintendo characters fighting against different enemies and bosses from different Nintendo franchises and the Nintendo characters uniting to fight against whatever enemy is causing the dimensional shenanigans and whatnot.
And when I saw that, I was like, "Huh, thinking about it, it's because of Nintendo and Koei Tecmo that we got Marvel Ultimate Alliance 3, since Nintendo funded and published it and KT developed it. And Koei Tecmo did both Hyrule Warriors and Fire Emblem Warriors, both of which started with a crossover-focused entry and then later got an entry connected to a main game. A Nintendo-crossover game done by Koei Tecmo doesn't sound like an impossibility."
And it would give Nintendo fans what they've been asking for in regards to Nintendo crossover interaction and another attempt at a crossover story like Subspace Emissary, except rather than trying to tie in and put a whole crossover story into a multiplayer focused game 1/3 it's size, it's making a singleplayer/Co-op focused game along with the story in mind, between characters, level designs, enemies and bosses, gameplay mechanics, extra modes and whatnot.
And there would certainly be the possibility of more side characters appearing alongside the main heroes, especially if keeping the focus on team-ups. Like besides the usual characters like Mario, Link, Kirby and whatnot, if the focus has characters defending their worlds from empowered foes, they can add side characters of that main characters' world as playable characters, like being able to have a team of Fox, Falco, Slippy and Peppy(or Krystal) or depending on which Mother/Earthbound world is being defended, it could be Ness, Paula, Jeff and Poo or Lucas, Kumatora, Duster and Boney(or Flint).
And team-ups don't necessarily need to consist of characters from one world. Like one area could be a conglomerate of different NES Stand-alone game worlds that happened to get merged together. And they could add characters that can have an interesting team-up in terms of origin or something along those lines. Like having Link, Samus, Pit and Takamaru as "Team 1986", or something like Ice Climbers, Bubbles from Clu-Clu Land, Balloon Fighter and Mach Rider for a "Nintendo VS." Team-up, in reference to their Nintendo VS. System Arcade game versions.
Either way, IMO, if we ever get another Nintendo-crossover story like Subspace, it's not going to be Smash Bros that brings another one, between how much it took to make it and Sakurai wanting people to play to experience instead of just immediately spoiling themselves on the internet. But I certainly wouldn't mind a different attempt at a Nintendo-crossover game that was made with the story in tandem to account for gameplay, mechanics, level designs, characters, enemies and bosses, and whatnot. And after remembering Koei Tecmo and their experience with both Nintendo games and crossover-focused titles like Marvel Ultimate Alliance 3, I wouldn't mind if Koei Tecmo did a Nintendo-crossover take similar to M:UA3.