All games in Soundvoyager require stereo sound. All models of the Game Boy Advance don't have stereo sound, so headphones, speakers, a Game Boy Player (plus TV with stereo sound), or a Nintendo DS are needed. Each game is some variation on using stereo sound to center a sound effect or music cue in-between the left and right speaker. It's impossible to play Soundvoyager without sound.
There are 7 types of mini-games in Soundvoyager. All level titles are written in lowercase.
This is the main mode. Sound catcher accounts for 14 full levels, one tutorial, and two bonus levels. Each game starts in silence. Instruments fall from beyond the top of the screen down to the bottom. As they fall, they play some kind of music or sound effect. In addition to being far away vertically, the instruments are to the left or right of the player's dot. (That is, their sounds are louder in one speaker than the other.) They continuously make noise. Players move their dot left or right to line it up with the falling sound.
When the instrument reaches the bottom of the screen, if its sound is centered between both speakers, it is added to the background music for the level. Gameplay continues in this manner for several minutes. Over time, a song is built out of the individual effects. At most, two instruments are actively falling at the same time, and they are offset so one reaches the bottom first.
After the quick, introductory "sound catcher 〈voyage〉" level, the games branch into two paths. 6 of the subsequent games also branch into two paths.
There are a total of 32 levels, plus 2 bonus sound catcher stages - remix and shuffle. Remix takes each individual sound from the sound catcher stages and randomly selects them one-at-a-time. Shuffle randomly goes through full sound catcher stages. Both remix and shuffle are endless.
Additionally, credits and an "adjust volume" option are available. (This makes a total of 37 selectable menu items by the end of the game.)