The characters were in a different Smash World.
Yes I do agree that bringing everyone's worlds together would have been more interesting, but they still managed to create an immersive world.
I feel if they included the prologue into SE everything would have made more sense, but instead they left a lot of of up to interpretation.
Which was pretty easy to figure out. Tabuu is bad and trying to bring the world into Subspace, the bad characters remain bad, heroes need to band together to save their world. It's not that confusing. The only real confusing thing was trying to figure out what made Mr. Game & Watch so special. But everything is explained in the prologue and suggest everyone read it to understand. It really is interesting.
http://supersmashbros.wikia.com/wiki/Adventure_Mode:_The_Subspace_Emissary
I feel if they kept the main story line, worked in some of the prologue into the actual story, but instead had Tabuu suck the different franchises into Subspace. That would have made for a more memorable scene with fighting through mushroom kingdom and then all of a sudden the Great Fox is flying through Dream Land.
The overall Smash World was pretty basic, and the enemies were somewhat forgettable, but the originality was there. Melee had already done the jumping from world to world plot so they wanted to try something different. And it worked.
I got submerged into the Smash World. I don't give a **** that the backgrounds were plain, the characters were designed to fit that world perfectly. And the cutscenes worked perfectly. They helped to bring it all together. It was amazing seeing them the first time. Fox going 1 on 1 with the Halberd, Dedede slapping Bowser, Wario doing his **** face at the Ness trophy, and so many others.
The side - scrolling never really got stale for me. That's what the 1 player mode was meant to be. It was fun trying all of the new characters and being forced to choose some that are out of your comfort zone, so that kept the mode fresh.
No one expected character development, but it was in there. And better than any most of the recent video games story modes. You got a cowardly boy who watched his friend get stolen and did nothing to stop it. He finds someone on his journey who he can look up to and helps make him more courageous. He conquers the enemy while at the same time conquering his fears. He manages to muster up enough courage to save the helpless Pokemon Trainer. Ultimately becoming a better person.
R.O.B. watches as he commands an army of his brethren to selflessly sacrifice themselves for the "greater good". He is so ashamed of what he has become that he disguises himself. He is constantly watching his own kind die everyday to fulfil the duties that he commands them. All while he is serving a greater evil. He finally has seen enough of his people die and comes out of hiding to fight for them.
I can understand why 'repetitive side-scrolling', 'original landscape and enemies' and 'lack of other worlds' can be discerning to some people, but that in no way ruins the story. Sure it could make it better, but anything can be improved from what it is.
That doesn't make the Subspace Emissary any less of a fantastic and engaging journey through an immersive new world with all of your favourite Nintendo characters.
I loved Subspace Emissary. Sure it gets dull after a bunch of plays throughs, but so does any adventure game.
I'm sure if you go back and played it again you'd finally appreciate it.