Sonic 4 episode 1 sprites
When Sonic smashes Eggman's creations once again, he retreats into space, and Sonic gives chase on a rocket. Eggman seeks revenge on his perpetual arch-nemesis by rebuilding his best Badniks to go on a hedgehog hunt.
The story is simple: Some time after the events of Sonic 3 & Knuckles, Mad Scientist and aspiring world conqueror Dr. Each episode has four Zones with four Acts each (three standard levels and one boss fight per Zone), plus a final Boss-Only Level in each, making for a decently-sized downloadable game that Sega initially designed to test the waters for classic Sonic's return.
It's an Episodic Game, with only two episodes released, though having both episodes downloaded unlocks a short interquel. Sonic the Hedgehog 4 (not to be confused with the SNES unlicensed bootleg game) is a side-scrolling platformer developed by Dimps that is a modern-day throwback to Sonic's roots on the Sega Genesis.