How do you unlock characters in Super Smash Flash?
Luigi -- Clear Adventure on at least normal with Mario
Jigglypuff -- Clear Adventure on any difficulty with any character.
Cloud -- Complete 100-man melee with any character.
Crono -- Clear 3-minute Melee.
Naruto -- Clear Adventure with the original 13 characters.
Shadow -- Clear Adventure with Sonic, Tails, and Knuckles
Super Sonic -- Clear Classic with Sonic on Very Hard Difficulty without getting Game Over.
Zero -- Clear Adventure with Megaman getting Game Over on at least Normal Difficulty.
Young Link -- Clear Classic with Link on any difficulty.
Inuyasha -- Clear Adventure without losing any lives.
Mr. Game and Watch -- Clear Target Test with every character but him.
Mr. Incredible -- Clear Classic Mode with the original 13 characters.
Mewtwo -- Clear Adventure with Pikachu and Jigglypuff.
Lloyd -- Clear Adventure with any character after having one hour of total play time.
Blue -- Clear Adventure with Blade on at least