very good lemme just give u some ideas
you know u need to add events member the those little missions on smash brothers i think number 31 is when u beat gannondorf to try to get him. Those events. Also make it a little more easier to get characters. Add more stuff to adventure mode and make more modes by ur self dont relie on the game to give u ideas. You have to make more move buttons more items and more stages. Also keep making more characters. Also try and see if u can make it a multiplayer game like stick arena so i can own someone else. Try to make the fighting style just like the gamecube version. Add more ways to make a game. Like maybe things u can set how much percent u have and then u have to fight until that goes down. Or some other types of fighting modes. Add more last bosses such giga bowsers.