i'm write here...
I will give some things for you make in Super Smash Flash 2 Demo man:
Add Luigi and Shadow as a playable character
give 2 options of final smash to sonic: Sonic Combos, and Super Sonic. And to shadow too:Shadow Combos and Super Shadow
NOTE: GIVE MORE OR LESS TO THIS REVIEW IF YOU KNOW SUPER SMASH FLASH 2 DEMO