The blue cool dude with a 'tude has been fighting the forces of Dr. 'Eggman' Robotnik since for many years, using his supersonic speed to maneuver around and attack each of the wacky, colorful, and vast zones. Whether it be through Green Hills, Chemical Plants, or even the Space Colony Ark, he's been nearly everywhere. He even competed in the Olympic Games with Mario. Sonic has been in a wide range of video games and has acquired new abilities and experience, whether it be learning Chaos Control from Shadow, his iconic Spin Dash, or his Homing Attack first seen in Sonic Adventure.
In Smash Bros., he's fast with agility to match, so while he's no powerhouse, his mobility and sonic speed more than makes up for it. He's been buffed to have greater KO power this time around.