
Some games become legendary not just for being great, but because of how much their inspiration is felt in the games that come after them. Just think of how much Demon’s Souls has influenced the design of action RPGs or how many developers Destiny convinced that live-service shooters were the wave of the future.
This is not about one of those games. Sonic & Knuckles is remembered not for being influential, but for including one innovation so strange that it’s never been replicated again. When it launched on October 18, 1994, Sonic & Knuckles had the most unusual cartridge of any Sega Genesis game; the result of production issues at Sega that turned the game into one of the most memorable titles on the console.