This is the "classic" look. Created by the late Yasushi Yamaguchi (who also designed Tails), these sprites are characterized by:
The Sonic sprite sheet remains a valuable resource for animators, game developers, and fans. Modern game engines and animation software allow developers to easily import and animate sprite sheets, making it possible to recreate classic games or create new ones with a retro aesthetic. sonic sprite sheet
Sonic uncrossed his arms and stepped closer. “Rebuild it how?” This is the "classic" look
In game development and fan art, a is a single image file containing a sequence of 2D graphics (sprites) that represent various frames of Sonic the Hedgehog's animations. Developers use these sheets to create fluid movement by rapidly cycling through frames, such as running, jumping, or idling. Types of Sonic Sprite Sheets Sonic uncrossed his arms and stepped closer
And with that, he was gone—a blue blur across the newly restored hills, leaving only the pixelated ghost of a thumbs-up on the monitor behind him.