It should be a 3DS game (2GB) so...
Chun Li from Street Fighter (3D) 3rd Party guest
-With attacks inspired by both her games and her feature film
Zoroark & Mewtwo Five Pokemon characters again
Ideas for Zoroark's Moveset
Shadow Claw
Crunch/Bite
Thief-Steals items held by opponent
Double Team
Illusion
If Lucario Returns Cynthia should be a playable character, and Lucario one of the Pokemon she uses.
Toon Link, Toon Zelda/Tetra, Gannondorf, -the only Zelda Characters
Chibi Robo- with mechanical gadgets like helecopter alt. color Gold, & Red, Blue, and Green Metalic,
Krystal with staff, with outfits from both Starfox Assault & Adventures
Sonic Returns
Issac from Golden Sun, (Although I know nothing of him)
Marth as the only Fire Emblem Character with some of Roy's moves, (including a 48.75% chance of explosion durring Shield Breaker, and flames on a few attacks) and a final Smash involving Roy's sword, and summoning an invincible commandable Roy (using sword with touch screen) with lightning fast fire attacks until the final smash is over.
Mario with Dr. Mario outfit as alt. coustume
Room for Wi-Fi, and 3DS download Event characters up to 4 (Spare data)
Who likes Banjo Kazooie?
Microsoft'll never allow it...