Sonic the Hedgehog (1991)

Sonic the Hedgehog for the Sega Genesis is the first title in the Sonic the Hedgehog series, and the third appearance of Sonic the Hedgehog. The game's original programmer was former Sonic Team leader and series creator Yuji Naka, and the planner was Hirokazu Yasuhara. The gameplay was faster than any other game before it and amazed many people at launch. This was due to the Mega Drive's Motorola 68000 processor, whose basic speed and ability to handle 16-bit numbers gave it incredible speed compared to its predecessor, the Master System. Nevertheless, a separate 8-bit version, which focused more on exploration than speed, was later released for said system.

Story
Somewhere on South Island, Sonic the Hedgehog's animal friends are disappearing. When he discovers that the evil scientist Dr. Ivo Robotnik has been kidnapping them and converting them into robotic Badniks - all as part of a plot to collect a legendary treasure known the Chaos Emeralds - Sonic decides it's up to him to save them, and embarks on a quest to free his friends. As Sonic races through the zones, he marks them as his territory and frees the animals from their both their robotic shells and the egg-like prisons. After Dr. Robotnik is defeated for the sixth time at his hideout, he will flee and abandon his laboratory as Sonic returns to the place his journey began.

While completely optional during the game's progression, the Chaos Emeralds can be claimed by Sonic in the first five zones if he holds fifty Rings before completing the first two acts, taking him to the Special Stage (AKA "Secret Zone"). In the game's normal ending, Sonic will give the player a testing look before posing for the screen, and Robotnik will be shown after the credits juggling the undiscovered Chaos Emeralds with a "Try Again" message. If the player succeeds in collecting the six Emeralds before clearing the game, a more satisfactory result ensues - they will suddenly fly out of Sonic's grasp as they react in a circle and then teleport away as nature is rejuvenated on the island, astonishing Sonic. If this happens, Dr. Robotnik will be shown after the credits to instead be childishly jumping on the "End" sign.