While millions around the world are either nostalgically revisiting Kanto or heading there for the first time, Did You Know Gaming decided to mark the launch of Let's Go, Pikachu and Let's Go, Eevee with a lengthy collection of obscure Pokémon facts. There's plenty to dig through, including tidbits about the music, Pokémon designs, and mistakes that weren't caught before launch, but perhaps the most interesting revelation is that the original games almost ended up being much harder.
The Pokémon franchise would eventually give players the ability to challenge NPC trainers they had already defeated to a rematch, but a similar feature was once planned for generation one. Instead of triggering rematches with some special item, the original plan was for every trainer to battle you every time you walked in front of them, even if you've already beaten them. Thus, the entire game world would have been a minefield of rematches.
On top of this added challenge, the encounter rate for wild Pokémon was originally much higher. According to Tsunekazu Ishihara, CEO of The Pokémon Company, it would take over an hour to get through Viridian Forest, and half a day to get through a cave like Mount Moon. The development team rightfully decided that this was just too much and toned things down for the final release.