Rhythm Heaven/Unused

Development History
Towards the end of 2004, the team working on Rhythm Tengoku wanted to create a version of the game for the Nintendo DS as well, which had just been released. At the time they could not create a pleasing rhythm game that took advantage of the Touch Screen, so they focused on the Game Boy Advance version instead. Towards the end of development at the beginning of 2006, the Nintendo DS became a huge hit, so the staff revisited the idea, however it would've taken a long time to port the work they had already made for the GBA version, and as the game contained previously unreleased songs, they decided not to delay the game. During an interview on September 21, 2006, supervisor Katsuya Yamano teased the idea of a sequel for the Nintendo DS.

While working on the arcade version, the developers faced the challenge of figuring out what the next game in the series would be like, which wasn't easy. Director and chief programmer Kazuyoshi Osawa considered a control mechanic that involved the Touch Screen. The ability to touch the edge of the Touch Screen which would make a tapping sound was considered, but was determined to be too difficult, and so a flicking action was adopted instead. It took a little getting used to, however. Eventually, they realized that combining sound with the flicking action provided a good sense of timing, but they had considered returning to button controls all the while. The flick action took about two to three months for background research and more than six months to eventually adapt the control into Rhythm Heaven.

Osawa was in agony trying to figure out how to make the game fun on Nintendo DS. The team had sent a sample to Tsunku♂, who really tore it apart. After talking with him, he gave the concept that would eventually become Frog Hop, which became one of the very first games to be made for Rhythm Heaven. After this, Tsunku♂ became deeply involved with development, just as he was with the previous game. The team as whole was small but with effective leadership, being clear on what ideas are fun to play and which ones need to be scrapped, and sometimes assets would be used in ways the original person who made them could not have expected. Osawa was known to have drawn the original pixel art and written the text, which would later be redrawn by Ko Takeuchi and Kyohei Seki. On July 23, 2008, Tsunku♂ posted on his blog about the game, which would release a week later in Japan, titled Rhythm Tengoku Gold. On September 8, 2008, he posted about the release of Rhythm Tengoku Zen Kyoku-shu, a soundtrack release for both Rhythm Tengoku and Rhythm Tengoku Gold, released later on October 15, 2008. When it came time to localize the game overseas, careful consideration was made to make sure the game had the same impact on an American audience as it did for the original Japanese demographic. This included dubbing the songs into English, with the original development team overseeing and approving the new vocals. The staff in Japan would first translate the lyrics directly, and the staff at Nintendo of America would localize them. They took extra care to maintain the flow behind the gameplay. At one point, there were plans to include the Japanese vocals as an unlockable, but this was cut due to memory constraints. A remnant of this can be found in the ROM of the North American version, where two files labeled "STRM_072" and "STRM_073" can be found, these being the Japanese versions of Struck by the Rain. The idea of including a dual soundtrack would later be realized in Beat the Beat: Rhythm Paradise (exclusively in the European version) and Rhythm Heaven Megamix (in all overseas releases).

A demo of the game was shown off at E3 2008, and Nintendo Media Summit Fall 2008 , with this version showing some differences like the names of the three games present, and a different logo. On April 17, 2009, Tsunku♂ posted on his blog announcing the game's release in North America under the title Rhythm Heaven, which had released around two weeks prior. It would release the following month in Europe under the title Rhythm Paradise. On June 3, 2009, another blog post was made to announce the release of Rhythm Tengoku Gold Kokunai-ban Kaigai-ban Zen Vocal-shu, which focused on the vocal songs and their dubs in other languages present in the overseas releases, released on July 29, 2009. The game would later be released on September 24, 2009 in South Korea, titled Rhythm World.