There's a cheap trick (i think...)
Very cool game to kill time with. I don't know how fly was intended to work, but I was able to ascend the levels extremely fast by tapping fly then jumping up again. It barely uses any spirit meter at all. I died at around 6800m when I didn't get ANY spirit recharge for a few hundred meters. Not sure if this was the intended behavior, but it made the game a bit too easy.