You may or may not have heard about this, but for those unaware, an early build of Sonic 1 was released to the public on New Year’s Eve (or New Year’s Day, depending on your timezone) by the awesome people over at Hidden Palace, a community dedicated to unearthing video game prototypes and such. There are a ton of minor, as well as major, changes showcased in the prototype, including Zone name changes, completely different looks for zones, minor music differences, and the list goes on. I recommend reading the page on the early build itself on the Hidden Palace website (which I linked above earlier); it’s really fascinating stuff, and they even provided a download for the prototype, so if you have a Mega Drive/Genesis emulator handy, you can play it for yourself!