How to Unlock
Captain Falcon is unlocked by playing Special Smash five times, then fight Captain Falcon in Mute City.
Defeat 80 foes in Endless Smash, then fight Ness in Onett.
Complete Classic mode as Sonic, then fight Tails in Chemical Plant Zone.
Complete the event, "Great Rivals", then fight Waluigi in Choco Mountain.
Complete Classic mode as any pokémon on an intensity higher than 3.0, then fight Lucario in Pokémon Stadium 2.
Complete the event, "Pokémon Tournament", then fight Charizard in Pokémon Stadium 2.
Play 25 matches on a Star Fox stage, then fight Falco in Lylat Cruise.
Create a custom stage and play on it, then fight Ganondorf in the Tower of Hera.
Complete the event, "Chapter 6" on Hard mode, then defeat Palutena in Palutena's Temple. (Chapter 6 requires getting Dark Pit.)
Complete Classic mode as Ness on an intensity higher than 5.0, then fight Lucas in the Devil's Machine.
Play 10 matches on the Comet Observatory as a Mario character, then fight Rosalina in the same place.
Play the game for a combined total of 10 hours.