I like that little echo the piano has as well, gives a feel of being in a hallway somewhere and just enjoying the music as well. As for it being ambient, I would have to disagree and say it is classical instead as this is piano only. Ambient is more of a genre where you let the sounds paint the scene and tone for a place.
Very nice piano playing however, the echo effect is a nice thing worked with on this piece too. Not too bad at all.
Overall, nice classical piano piece.
Thanks for the review, and thanks for clearing up what genre this should've been classified as.