The piano at the beginning was wonderful, i love how you switched it up into the guitar, but i would have enjoyed it more if you had left the piano in with the guitar somehow. Very nice though :)
I really liked the piano part at the beginning, you're very good at piano. Sounded a bit like something Ludovico Einaudi might come out with. When the guitar part came in it wasn't really my kind of thing, but that doesn't matter at all because that's the kind of song you want to make. So the only constructive criticism is that the guitar sounded a little out of time in parts, but as you said this is just a preview so you're probably doing something about that.
Good work mate,
Please contact me if you would like to use this in a project. We can discuss the details.