Sonic the Hedgehog 4 goes episodic this summer - GameSpot

Project Needlemouse revealed as side-scrolling sequel to speedster's original Genesis trilogy; Episode 1 confirmed for Wii, Xbox 360, PS3.
Sonic is back for his fourth installment in the classic 2D series, revamped from the ground up.

Sonic the Hedgehog 4: Episode 1 Review - GameSpot

Sonic the Hedgehog 4: Episode 1 - Game - Nintendo World Report

Sonic the Hedgehog 4: Episode III, Video Games Fanon Wiki

Editing Sonic the Hedgehog 2006 (lost build of Tokyo Toy Show tech

Sonic the Hedgehog - Wikipedia

Is Sonic 4 after Sonic 3?

Is Sonic 4 a mainline game?

Sonic the Hedgehog 4: Episode 1 News - GameSpot

Sonic The Hedgehog 4: Episode I Review –

Hey Sega, why is Sonic 4 episodic? – Destructoid

Sonic 4 Episode 1 » SEGAbits - #1 Source for SEGA News

Sonic the Hedgehog 4 Episode II

Sonic the Hedgehog 4: Episode 1 Reviews - GameSpot