Sonic the Hedgehog Extreme

About

Sonic Extreme was a prototype video game created by Vision Scape Interactive in May 2003. Proposed as a spin-off to Sega's Sonic the Hedgehog series, Sonic Extreme featured Sonic and Shadow riding hoverboards in a Green Hill Zone-themed open world, with gameplay likened to Tony Hawk's Pro Skater. It featured three gameplay modes, which included searching for keys and Chaos Emeralds and fighting or racing another player.

Source: IGDB