Mushroomguy12
Smash Hero
This is probably unlikely, but part of me thinks it would be cool that if after Wave 6, they added an alternate ending credits or title screen showing all the playable characters (booster course included) like they did in Double Dash and Wii. Would be a nice send off to a game that's been supported for so long throughout technically 2 generations, similar to the "Everyone is Here" poster for Smash Ultimate as well.