Sakurai did say all characters would play identically between both versions, so changing any movesets/etc. would alienate the other game owner if applicable. Same reason for the same roster(not to say more characters can't come in one version at first with the rest being available for the other, shortly after or right away).
Anyway;
-Bonus Mode: No effect on how a character plays, but is fun.
-Coin Mode: Probably a lag issue due to too many objects on the screen(doesn't explain Bonus Mode missing in the 3DS version) returning. It's a fun mode, although I take Bonus over it any day.
-More space for Individual Target Tests now. Or more in general.
-3DS' Classic Mode was fine, but a separate one that has more stuff to do would be cool too.
-Item Ratios and more Items. I.E. Red Shell. I could see the Item list being the same, but the ratios back.
-When they're all unlocked, an Assist Trophy/Poke Ball/Master Ball ratio for which one shows up. Might've been less of an issue for Poke Balls in earlier games, since some "cute" Legendaries drop items like Trophies, so... I can see why controlling which one shows up could be a bad thing. I mean, the other modes would be lesser used, so the decision is still reasonable.
-A full opening as well as all the character trailers.
-Since it has no effect on gameplay, different victory themes or victory poses would be cool. I do realize re-animating every pose is kind of hard, so victory theme updates is fine.
-Announce major DLC outside of a Mode and basic balance/bug fixes, please.
-Assist Trophies that have less lag/framerate issues.
-The return of Adventure Mode(I doubt SSE would work since the biggest seller of it was the cutscenes alone).
-I cannot erase any data beyond erasing the full game data from the SD Card. Seriously, just no. Let me erase characters so I can unlock them again, Etc. Any Trophy or Music I would erase could easily be gettable as a Random Drop if you already met the original unlock condition. Same with Stages, etc.
-All-Star Mode was fine in the 3DS version, imo. Make it more like Melee this time, by setting you up against 1, then 2, then 3, then 4 enemies after a while. And a random final battle akin to the 25 Mr. Game & Watches. You could move the number of enemies up or down based upon who you fight as well. And of course weaken/strengthen them slightly based upon the number alone. Much like how many Fighting Teams are weaker than general characters.
-Smash Run having Race to the Finish back is nice. Return it as a separate mode, please. Whether it's platform heavy enough to be similar to a combination of this and Board the Platforms, or closer to the 64 version, by fighting a random member of a Fighting Mii Team, using one of each style(and no custom power-ups, but random custom moves cause that's how they work. Or no specials, I guess. Either way, show all 3 styles).
-I want my Event Mode(I mean, if Tower of Smash is real, it's the same idea to a degree, but eh) back.
-I would not mind an optional mini-game to find Trophies, much like Coin Launcher. It was not a bad thing, it's just that it also allowed you to get Stickers... which were a dime a dozen. In other words, make every type of collectable material available somewhat easily with none overpushed while others were harder to get than they should be. For the record, Trophy Rush costs too many to play for me to like it.
-Special. Smash. Yeah.
