This is kinda nice. Maybe you could make the flowing water sound that starts around 0:03 more stereo, some reverb or chorus to make it feel more involved. Personally, I would add some bass intrument or instruments at 0:40, because as it is now it feels a bit empty. If you wanna keep the calm vibe, you could've probably used a sine wave or organ synth in a low pitch.
I don't know, but the song's nice so nicely done.