You need to get the widgets from one side to the other so they can be manufactured. Press D and K to give them a boost! D or Right Tap controls the top (plus) row. K or Left Tap controls the bottom (circle) row. For mobile Middle Tap controls both rows. You can make charts easily with this! The "Tutorial" sprite inside can help you with learning it.
Rhythm Tengoku is made by Nintendo. All sprites are vectors of Nintendo-created content. I do not own Rhythm Tengoku or its ideas, only its recreation.