The game was released in Japan in June 2015[1][2] and in North America, Europe, Oceania, and South Korea throughout 2016.

The game uses the traditional control scheme featured in the original Rhythm Tengoku, which uses the A, B, and directional buttons on the Nintendo 3DS.

The game can be optionally played with the stylus, though controls are more simplified compared to Rhythm Heaven.

Ratings for the Rhythm Games are now awarded based on a score meter indicating how well the player performed.

[3][4] Megamix features a Story Mode in which players try to help a character named Tibby reach Heaven World, his home.

Some older Rhythm Games that returned in Megamix (such as Karate Man, Shoot-'em-up, Micro-Row, and Air Rally), received a prequel version, an easier version which takes the original name and description of each game, and has new graphics and an alternated music (to match the music style of the new rhythm games featured in Megamix), while the original Rhythm Games have been labelled as sequels and are given new names (e.g. Sneaky Spirits from Tengoku is labelled as Sneaky Spirits 2 in Megamix, Glee Club from Heaven is labelled as Glee Club 2 in Megamix, and Figure Fighter 2 from Fever is labelled as Figure Fighter 3 in Megamix).

Some of the returning games from Tengoku and Heaven (DS) have added new music and redesigned graphics.

Masami Yone, the director of Rhythm Heaven Fever, assumed the same role for Megamix.

Ko Takeuchi returns as the art director, and Yoshio Sakamoto as the general producer.

The game was first announced near the end of a Japanese Nintendo Direct on January 14, 2015 in Japan, when Satoru Iwata is seen involved in a Nintendo Direct take of Karate Man Returns, before the gameplay footage is shown.

In making music for the games (the prequel of Karate Man for example), I'd have a strong feeling for it because it was unexpectedly tough.

He brought in Tokimekist (Chi-chan, Rino Hirayama, Mai-chan, Yurinko) to record the song.

In recording "For That One Big Tear", Tsunku♂ really liked the song's melody and lyrics, so he brought in Hikaru Ohashi, a singer from the Ishikawa prefecture, to sing.

He brought in Pajama Musume Club (Karen, Azuki Moeno, Hitomi Yoshida) to record the song.

The music video for "I'm a lady now/Hotzmic" was released (probably to promote Megamix) in Japan, in which the song is extended than the 1-minute version heard in the Honeybee Remix.

In 2016, Nintendo announced that the game would launch in North America, Europe, Australia and Korea "later" that year.

1 in Japanese charts maintained by Media Create, recording 158,000 copies sold in its first week of release.