Do you lie your phone on a flat surface (maybe angled towards you slightly) and hit notes index (and maybe middle) fingers? Or do you hold your phone like a traditional game controller and hit notes using your thumbs? The only other rhythm game I've played is LLSIF on my iPad which I play using the first position. So when I played Uta Macross for the first time on my android phone, I also played with the phone and my hands in a similar position.