Sonic Unleashed is an action game in which players assume the role of Sonic the Hedgehog in his quest to defeat the evil Eggman. Players mostly zoom across fantastical landscapes collecting gold rings and power-ups. Some sequences allow Sonic to transform into a wolf-like character as he explores different areas while beating up enemies with his fists and the occasional 'special attack' move. When Sonic wounds certain boss creatures, spurts of green fluid ooze from various afflicted areas. Cutscenes are sometimes lively and frenetic, involving enemy robots who shoot lasers at Sonic and a villain who electrocutes the hero.