While I'm at it...
Ridley (Assist) -- NOBODY HAS UNLOCKED YET
Barbara Bat from Daigassou! Band Brothers -- plays music
Ray 01 from Custome Robo -- tiny, flies around and fires arsenal
Grey Fox from Metal Gear -- slashes players
Devil from Devil World -- shifts stage
Excitebikers from Excitebike -- run across stage en masse
Samurai Goroh from F-ZERO -- slashes players
Heririn from Kuru Kuru Kururin -- UNKNOWN
Hammer Brother from Mario -- tosses hammers
Jeff from Earthbound -- sets off toy rockets
Knuckle Joe from Kirby -- punches and kicks players
Lakitu from Mario -- throws Spinies
Kat and Ana from Wario Ware -- slash across screen in "X"
Jill from Drill Dozer -- drills across platforms
Lyn from Fire Emblem -- slashes players
Little Mac from Punch-Out!! -- punches and uppercuts players
Metroid from... Metroid?
-- latches on to players
Labrador from Nintendogs -- blocks screen
Mr. Resetti from Animal Crossing -- drones
Isaac from Golden Sun -- pushes players with psychic hand
Saki from Sin and Punishment -- shoots and slashes players
Shadow from Sonic -- slows down time
Stafy from Legend of Stafy -- tackles players
Infantry/Tanks from Advance Wars -- shoot at players
Tingle from Zelda -- summons a wealth of items
Waluigi from Mario -- stomps and kicks players
Dr. Wright from Sim City -- grows buildings that toss players
That... That just saddens me. There's some cool ones in there, but a lot of ones I'd expect are totally ignored. That is such a small amount.