We often think back to Pokemon Red & Blue as the beginning of the Pokemon legacy, but of course, they were actually iterations of the original Pokemon Red & Green which were released in Japan and then altered in various ways before making it overseas two years later as Pokemon Red & Blue. Here's a little chitchat about it...
Pokemon Red & Green were originally released in Japan in 1996, and then received a follow-up in the form of Pokemon Blue, which made several minor updates to the original versions and served as the basis for the graphics, game engine, and script for the overseas releases of Pokemon Red & Blue.
Most of the changes consisted of minor bug fixes and other incremental updates to the games' features, but two big differences from R&G→B that stand out are the following:
1) Every Pokemon sprite in the game was redesigned, and
2) the layout of Cerulean Cave was completely restructured.
As far as the sprite changes go, some were improvements and others were... not so much. Also, I wonder why they altered Cerulean Cave out of all the layouts that they could have potentially adjusted. 🤔
Anyways, it's a fun little gem to own!
PS: The Missingno glitch never existed in the Japanese games. Weird, eh?
PPS: Interestingly, the Japanese version of Pokemon Blue released in 1996 was only available to subscribers of Korokoro Komikku before being made available to the general public in 1999.