In 2018, at the Game Developer Conference, designer Hirokazu Yasuhara talked about the creation of Sonic, which was by no means an easy decision. Sega wanted a character that could curl up into a ball and roll around to deal damage, he said, but there were other options for the look of the mascot, as developed by Sega's team AM8.
“[Sega said] we definitely want to see something like an old guy with a moustache,” Yasuhara said in a discussion reported on by Eurogamer. “We also want to see something like a hedgehog, or porcupine, as well as a dog-like character.”
So, to narrow down the options, Yasuhara planned a trip to New York. Taking sketches of the characters with him, he surveyed random people in Central Park to find out which one most resonated with Americans. He found that the hedgehog was most popular, followed by the “old guy with a moustache” (who later became Sonic's antagonist, Eggman), and the dog character.
Yasuhara came to the conclusion that the hedgehog character “would transcend race, gender, different types of people — everything.” He reported his results to Sega, and Sonic was greenlit for stardom.