Adventure Mode?

[Locked Achievement]

I had an idea that some characters could end up in outer space, say, Olimar and Lucas could be in outer space fighting some impossible boss (that cannot die) before some other character like deoxys appears and you are then able to kick their ass.

Well, looking at the list of characters, some of them do have some relevence to outer space, so that could contribute to whatever happens along the adventure.

Also, does anyone have any ideas for Bosses?

[Wes]

Here's an idea.

Basically, the Villain characters will be provided as the "bosses" of each level. In the Mario stage, you'll go through, IDK, Mushroom Kingdom ala Melee. Reaching the Checkpoint will bring you into a fight with Mario and Peach (Luigi replaces one of them if your player character is Mario or Peach). You continue further on, and you reach the Boss Battle. Boss Battle being Bowser in his Koopa Klown Car. Beating this boss will give you a chance to fight to unlock Bowser in the game (Except, we've all decided that Bowser was going to be a starter =/)

These Villain characters will fight differently than the actual fighter battles (You'll end up fighting DK and Diddy normally, while K. Rool will have Canonballs raining down upon you. King Dedede might get possessed by O2, so you gotta knock his HP down to whatever. Ridley called his buddy Kraid to help destroy you.) And through multiple play throughs, you'll eventually unlock the entire cast of villains (If I do believe, Bowser, K.Rool, Ganon, Ridley, Bowser Jr., Dedede, Wolf, Mewtwo, Porky Minch, and ROB (If we count the whole Ancient Minister gig from Brawl)). The other characters, could be unlocked through Classic Mode, minigames, Event Matches (?) and hell, even through Trophy Collection

IDK, platforming overload?

You forgot Wario, Waluigi, Masked Man, Deoxys, and Samurai Goroh.

[Kriven]

Do not like, it doesn't leave room for Adventure-Specific bosses (such as Petey) which were really freakin' cool.

[D2S-Speed]

Instead of telling a storyline of each character lets try to focus on whether or not we will be using this kind of idea. I however would vote for it.

[Zabi]

Why not just combine both types of bosses?
Something like: Each stage has something like a "mini boss" (appearing in the middle of the level) and a end boss (at the end). One boss would be a playable character who you could fight against under certain conditions, and the other one would have a life bar like in Brawl's SSE. Which of both comes at the end or the middle should depend on the ideas for the bosses.
Example:
Pokemon Level: plattforming... - Mini Boss: Mewtwo / Deoxys - more plattforming... - End Boss: Champion (Lance or Blue) or even Team Rocket (lol) with 3-4 awesome Pokemon.
When you do that with all franchises, you should come up to ~ 15 levels. Considering the length of those stages, each walkthrough should contain about 5-7 randomly chosen levels.
What do you think?

[Locked Achievement]

so... your saying wed have to do a LOAD of spriting for one level. You could do something along those lines, but that would have to last longer than just one level

eg, say this is for Pikachu; There is a couple of levels, then you fight Jigglypuff, then a few more levels, then Lucario. Then a couple of platforming levels, before you choose one of the two (Jigg or Lucar) to team up with you and fight deoxys and Mewtwo. Im not saying it should be this, but something like this could allow plenty more levels with less spriting.