Gold and
Silver were first publicly showcased at November 1997,
Nintendo Space World Expo in Japan, becoming the most popular exhibit at the program. Unlike the previous game in the series,
Pokémon Yellow, the new titles were announced to be more than a small upgrade to
Pokémon Red and Blue. Instead, they would feature a new storyline, a new world, and new species of Pokémon.
Gold and
Silver were designed for the Game Boy Color, allowing them full color support and more detailed
sprites. Other additions that were shown included Pokémon breeding, held items, an in-game gadget known as the PokéGear, a real-time internal clock, and
backward compatibility with the previous games in the series. During an
ABC News interview, president of
Creatures Inc. Tsunekazu Ishihara gave insight into the brainstorming process for developing new Pokémon species. He explained, "The ideas for each of these monsters came from the imagination of the software developers at Game Freak who get these ideas from their childhood experiences, including from reading
manga, a style of Japanese comic books. Ideas come from scary experiences they had as kids, catching insects, and so forth. So from these experiences in childhood, these ideas for Pokémon came out". In the same vein as the Pokémon
Mew of
Red and Blue, the exclusive Pokémon
Celebi was included in the
Gold and
Silver games but is only accessible after attending a Nintendo promotional event. The first official event offering Celebi was
Nintendo Space World 2000 in Japan, in which 100,000 attendees would be awarded the rare Pokémon. In order to be selected, players had to send in a postcard to enter a lottery for one of 100,000 certificates of Celebi, allowing them to enter the event and obtain it. Ishihara stated that
Gold and
Silver started development right after
Pokémon Red and Green were released in Japan. The original intention was to release the game in 1998, even synchronizing with the supposed end of the
anime's
first season. Development issues, worsened by Game Freak being sidetracked with
Pokémon Stadium and the localization of the first generation, led the game to be postponed, and the original release slate was taken over by
Pokémon Yellow. Programmer Shigeki Morimoto stated that part of why development took three and a half years was due to being a small team of only four programmers.
Satoru Iwata, then the president of
HAL Laboratory who would later become Nintendo's CEO, helped the team by developing new tools for compressing the Pokémon graphic code.
Junichi Masuda composed the game's music on an
Amiga computer, converted it to MIDI data and reconverted again for Game Boy Color.
Unused and cut content In 2018,
ROM images of the early-in-development Japanese-language demo shown during the 1997 Nintendo Space World presentation resurfaced: two
debug versions of the games, and two versions that were modified to work on normal
Game Boy hardware and most emulators. These ROM images were only rumored to exist until they were anonymously posted on the "
Pokémon Reverse Engineering Tools" (PRET)
Discord server in May 2018. The demo was quickly shared with members of the website
The Cutting Room Floor. The ROMs were analyzed and translated, and
The Cutting Room Floor went on to release a spreadsheet containing all the information they had discovered, which includes a list of Pokémon species, Pokémon "moves",
items,
non-playable characters,
maps, and music. The ROMs were first released anonymously onto
4chan's /vp/ board in May, with a formal
The Cutting Room Floor release coming later that day. The demo has a larger world map than the final game (which itself is based on the entire
Japanese archipelago, unlike the final region, which is based on the Kansai region of Japan), and includes around 100 unused and changed Pokémon designs. Additionally,
Pokémon creator
Satoshi Tajiri has revealed four unused designs that would have been included in the original
Pokémon games. While
cut content is not uncommon in video games, the volume of cut content in the
Gold and
Silver demo has been described as "overwhelming". Matthew Byrd, writing for
Den of Geek, stated that a lot of design work had gone into the Pokémon that were eventually cut, suggesting that Game Freak might have taken them out during the testing phase due to
balance issues. ==Release==