Twenty years ago today, Sega released the first Sonic the Hedgehog videogame. It was a joyous occasion—and it was also my dad's 41st birthday. (Happy 61st birthday, dad.) ...

He’s Avis to Mario’s Hertz. Or, if you prefer, Pepsi to Mario’s Coke. He’s Sega’s Sonic the Hedgehog, and he turns twenty on Thursday. And even if you know more about him than I do, you don’t know ...