I loved every bit of this! And you know, I couldn't place it before but the first half of this piece I get A Link To The Past vibes. Not so much the intro (which is awesome), but once we get to 1:18 or so. Then the second half of the piece sounds more like FF territory. Overall I like how you keep this pretty much in key, but at the same time are able to keep it harmonically interesting. You also seamlessly merged these variations into one big movement, despite their different mood changes. The biggest mood changes to my ears seemed to happen towards the later sections (and of course when you change it up to the Scherzo).
But another notable change was around 10:30, which sounds like a waltz to me. This is a very cool section! I also feel like you ended with a romantic flair, which to me, is another big mood shift!