Alex Kidd in the Enchanted Castle is a 1989 platform game released for the Sega Megadrive/Genesis. It was developed in-house by Sega as a competitor to the Nintendo Mario games, which were hugely popular at the time.
Developed by Sega and released for the Megadrive/Genesis in 1994, Sonic & Knuckles is a spin-off from the main Sonic series and the sequel to Sonic 3, this time with Knuckles the Echidna as your sidekick.
Sonic the Hedgehog and Miles “Tails” Prower return in 1994‘s Sonic the Hedgehog 3 – a game with a new graphical style, and a – thankfully – fixed two-player mode.
Released in 1992, one year after the classic Sonic the Hedgehog, Sonic the Hedgehog 2‘s big contribution to the series was the introduction of two-player games of Sonic. It was also a Japanese/American co-production this time, by Sega Technical Institute.
When Sega bigwigs asked their talented designers to create a video game character that would become the company mascot, the designers rubbed their chins for a while, then came up with a blue hedgehog, called Sonic.
In fact, the designers were so enamoured with their new creation that they changed their name to Sonic Team as they developed the game.