Beat Planet Music is, as the title would suggest, a rhythm action game. Each song represents a connection linking two cities; notes scroll down different lanes, and the the player must move their cursor from lane to lane and hit each note in order to play the music. As the player clears different songs, new samples are unlocked in the other mode: the song editor.
The meat of the game is the Song Editor mode, where the samples that make up the in-game music can be used to put together new tracks. Songs can be saved to the memory card, and played in the game's trial mode. You can even take samples from your own CDs and use them in your songs.