SSBS has a gameplay-style simalir to SSBB. However, most of the characters in the game, including newcomers, aren't clearly overpowering the other.
There are 30 characters in all.
Fireball (Standard) Fires a small projectile made out of fire that is sort of weak
Cape (Side) Mario uses the cape power-up from Super Mario World to reflect enemies and projectiles
Super Jump Punch (Up) Mario jumps up and hits the opponent causing coins to appear out
Fludd (Down) Mario summons Fludd ("F.L.U.D.D.") to push opponents back with water