Pokémon LeafGreen Version, and its sister game, Pokémon FireRed Version, are remakes of Pokémon Red Version and Pokémon Blue Version to catch and trade the original 150 Pokémon (along with some from additional Pokémon from Pokémon Gold Version, Pokémon Silver Version and Pokémon Crystal Version), and enable them to be traded over to Pokémon Ruby Version and Pokémon Sapphire Version. Both versions came with a Game Boy Advance Wireless Adapter for wireless multi-player.
- Additions made to FireRed Version & LeafGreen Version from Red Version, Blue Version & Yellow Version:
- Pokémon Breeding
- Pokémon Genders
- Move Tutors
- Move Deleters (For deleting the HM moves)
- Various Poké Ball types (Such as the Heavy Ball)
- Shiny Pokémon
- Split Special Stats (Attack and Defense)
- Protagonist Gender Option
- Organized Pocket Bag
- Trainer Battle Rematches (Via the VS Seeker)
Additions made to FireRed Version & LeafGreen Version from Gold Version, Silver Version & Crystal Version:
- All Pokémon up to #386 are compatible with and can be traded to and from FireRed Version & LeafGreen Version.
- Improved graphics on par with Ruby Version, Sapphire Version and Emerald Version.
- Running shoes
- Double Battles
- Pokémon Abilities
- Pokémon Natures
- Sevii Islands that can be accessed near the end of the game. Three are unlocked after you defeat Blaine, with the last seven being unlocked by defeating the Elite Four. The islands feature some events, Generation II Pokémon that were excluded in Ruby Version, Sapphire Version and Emerald Version, and the Battle Tower.
- Updated multi-player abilities, including a feature called a Union Room, which required the Game Boy Advance Wireless Adapter. This room was resembles the Nintendo DS's Pictochat, where nearby players would appear to in the room to talk, trade and battle.