Very lovely piece... I don't have much to say, enough has been said already by others. It's a lovely progression, and you did a marvelous job tweaking the melody and changing it up. Left hand is fine, you can add another phrase or change one to have a different pattern in the left hand, but I find that it is fine how it is. And I agree with Robin, it's more pop than minimalist, this is actually the style I like to use when I improvise, so I connect with this very well. I'm glad I'm not the only one who does stuff like this.
From what I could tell, Rob was just talking about tweaking midi information for a more realistic playback. That's fine if you're going to promote your stuff using midis, but I say don't worry about it. Live performance does this for you.
This is so pretty I could listen to it all day.... or play it all the day. It seems simple, I would have a field day improvising with this material.
