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.Featuring enhanced gameplay elements, including the classic Sonic Spin Dash, and the versatile Homing Attack, Sonic the Hedgehog 4 Episode I picks up right where Sonic and Knuckles™ left off.. The sequel fans have waited 16 years for is finally here - Sonic the Hedgehog 4 Episode I! Eggman's back, and in an effort to finally rid himself of Sonic, he revisits – and improves – the very best of his creations.