Kanto Expansion Pak

The Kanto Expansion Pak is a ROM hack of Pokémon Red that expands the original generation with scrapped Pokémon, regional variants, cross-gen evolutions, and Paradox Pokémon related to Generation 1.
It attempts to remain as faithful as possible to the game's design specifications while doing this, ensuring that the RBY OU metagame does not deviate significantly from its roots. Thus, it doesn't include generational gimmicks or do any attempt to "rebalance" the game to not heavily be based on Snorlax, Chansey, and Tauros. It also aims to be compatible with any Gen 1 metagame, allowing tiers like Monotype, LC, NFE, Nintendo Cups, and more to be at least playable for the average user. The original Pokémon are left completely unchanged (including the lack of type changes introduced in later games) and are balanced around instead.
Furthermore, the game includes multiple changes for quality of life, such as allowing you to capture every Pokémon without the need of trading, a Move relearner, and "Super Training". It also returns Super Gameboy Palettes back into the game, as well as including unused music and backports from later Pokémon games.