Sonic is a series of games where you go really, really fast. That's it. Sonic was designed to be a fast dude with an attitude, who was much more cool and fun than any of the competition out there. That's why he became so popular. Sonic has had a lot of different looks. He's had dozens and dozens of games, shows, and toys—because he represents the spirit of fast freedom and no responsibilities. He wags his finger naughtily and beats up an old dude with bad hair. He's teenagerdom personified as a blue hedgehog.
Except in the comics. There, he's more of a meditation on Dresden, destruction, and murder. He watches his friends die, even seeing his loved ones cradle their families' corpses, in tears. He lives to see his entire village bombarded, and there's nothing he, with all his speed, can do about it.
Where's the fast-loving funster we all love? Well, there's one scene where he kneels beside a grave, eulogizing all he's lost. Or how about the scene where Sonic goes to see the corpse of his crush, slowly, agonizingly, his pain writ all over his face? That's the cool, fast dude with an attitude we all know and love. F'sure. Oh, and also, sometimes, he's a werewolf.