You may or may not have heard of this (It's fairly new) But there's this flash game called Auditorium that is perfectly suited for iPhone/iPod touch! Now I know it's flash, but it should be fairly easily remade. http://www.playauditorium.com/ Basically, each orb controls the flow differently. There are the basic ones near the beginning, like Up, Down, Left and Right, but then later on you get into one that causes the flow to Spiral and such. Your goal is to get the flow to move over the Audio Bars, which fills them up and causes an instrument to play. When you see different coloured Audio Bars, you must direct the flow through a ring of that color before it will fill the Audio Bar. It's quite a fun game.