Unlike Pokemon Red and Pokemon Blue which was released in worldwide countries, Pokemon Green was released only in Japan.
The infamous Lavender Tower music is slightly different than in the other versions. However, the reason was not because of the "Lavender Tower Syndrome", which allegedly caused people to suffer from nosebleeds or even madness, and even drove some to suicide. Contrary to a myth that was first spread in 2010, no such incident ever happened. The reason why the melody was tweaked for the other versions was to make it less jarring, as the high frequencies could indeed be uncomfortable.
Although this version is identical to Pokémon: Versão vermelha (1996) and Pokémon: Versão azul (1996), it contains noticeable differences:
- Unlike the other Pokémon titles for the Game Boy, this version has a gray cartridge.
- The sprites of most Pokémon are different, giving them a "prototype" kind of style.
- It is explained that the old man blocking the way in Viridian City is drunk and has to sober up. This was changed in the international version with the explanation that he is waiting for his coffee.
- The Cerulean Cave in which the player is searching for Mewtwo has a different layout. It was changed for the international releases, as the cave was considered too difficult for western players.
- Evolved Pokémon can be caught in the wild, even those that have to be traded in order to evolve them. This makes it easier for the player to catch all 150 Pokémon without trading.
It was discovered that simply replacing the Japanese text with English text was impossible. Because of that, the entire source code had to be rewritten from scratch for Pokémon: Versão vermelha (1996) and Pokémon: Versão azul (1996) in order to make translations possible.
In Japan, a very detailed map was included with the game.