I think the percussion could have been mastered slightly quieter. The song really starts becoming calm around 0:37, before that it almost sounds like something you'd hear in a puzzle game. I really like the guitar coming in at 1:01, a lot could be done with it. It gives a very calming vibe, mixed with the other instruments. Also, I heard a key change at 1:25, but it felt like it was going from walking on beach kind of calm to walking into a cave kind of calm. Which makes me think, since you didn't know where to go with this... what if you were to add in some crystalline-sounding bells, or something similar? Anyways, sorry if this is a pain to read. :P