One talented Pokemon fan has modded HeartGold & SoulSilver to include Overworld encounters, and trainers are dying to play it.
Pokemon Heart Gold & Soul Silver, TM Locations, heart gold pokemon locations
Pretty happy with my rework for wild encounters : r/PokemonROMhacks
Translations - Pokémon: HeartGold Version, pokémon heartgold
Pokemon modder adds wild overworld encounters to HeartGold & SoulSilver - Dexerto, heart gold pokemon locations
Review: Pokemon HeartGold / SoulSilver – Destructoid
Pokemon modder adds wild overworld encounters to HeartGold & SoulSilver - Dexerto, heart gold pokemon locations
Pretty happy with my rework for wild encounters : r/PokemonROMhacks
Pokémon HeartGold & SoulSilver - Champion & Red Battle Music (HQ) , heart gold pokemon
Pokémon Heart Gold & Soul Silver - New Areas, heart gold pokemon league
Pokémon HeartGold & SoulSilver - All Legendary Pokémon Locations (HQ) , heart gold pokemon locations
Planned All Along: Pokémon HeartGold (Part 3), heart gold pokemon locations
Pokemon Heart Gold & Soul Silver, TM Locations, heart gold pokemon locations
Pretty happy with my rework for wild encounters : r/PokemonROMhacks
Pokémon HeartGold and SoulSilver Concept Art & Characters, heart gold pokemons