Like its predecessor, Sonic the Hedgehog 2 had both a 16-bit and 8-bit version, and both versions had different stories. However, most of Sonic 1's sales came from being a pack-in to the Genesis, with 4 million selling standalone, so Sonic 2 is technically the best-selling standalone game for the console.
It is the second-best selling Genesis/Mega Drive game of all time, selling over six million copies, only outsold by its predecessor's 15 million mark. The sequel to the original Sonic the Hedgehog, this game introduced Sonic's sidekick Tails, along with Sonic's Emerald-charged Super Form.
