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.

Is Sonic 4 after Sonic 3?

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

Sonic the Hedgehog 4: Episode 1 Review - GameSpot

Sonic 4 Ep 2 Screenshots - Features Sonic On Tails Action

Wah wah wah Sonic the Hedgehog 4! – Destructoid

Sonic the Hedgehog 4: Episode I (Game) - Giant Bomb

Sonic the Hedgehog 4 (Video Game) - TV Tropes

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

Sonic the Hedgehog (2006), Sonic Wiki Zone

Sonic the Hedgehog 4: Episode I — Вікіпедія

Sonic 4: Episode 2 Archives - Sonic Retro

Sonic 4 Episode 3 Was Planned By Sega But Was Cancelled - My

Sonic the Hedgehog 4: Episode I - Wikipedia

Sonic 4 announced in episodic form

Sonic the Hedgehog 4: Episode 1 News - GameSpot