So I listened to this when you first posted. I needed some time to process such an immense piece lol, and I relistened tonight.
First off, wtf dude. This is some serious composing. I could go on and on about how much I love this. Your variations were clever and definitely had a wide range of difference. I'd disagree about the sameness in harmony, I think you needed that to keep it coherent for the variations that went off into space (although it did wear on me a bit, probably because it's 30 min. long). You could have maybe drifted away from a C tonal center a bit more if you were worried about it, but it didn't really bother me.
I really admire the care you took in your transitions. Some were woven into the next variation, while other's had a more cadential ending. That's my favorite thing in writing a theme and variations. I really enjoy fitting each piece together seamlessly; so many of the style sound blocky to me...like here's a variation, then another, then another. But the key for me is to make it a piece of music, rather than have "pieces" of music.
Awesome changes in texture too. For the most part, it's like you knew right when I was getting bored of a thick texture, or bored of a slow one. You did a tremendous job taking the listener back and forth between so many different ways of presenting the theme.
I have to commend you on your score as well. It's pristine, and crystal clearly shows how much time you put into it. It was fun to follow along the journey the whole way through.
I only have a few criticisms, and just know they're probably subjective and minor. This was truly a masterwork.
The first time I listened, I really liked it, but knew I was missing something. It wasn't until the second time I listened that I figured out what it was. There is such charm in the theme, which I'm guessing you attached to that too. I really love the theme (never played the game before :P). Even though you dispersed the theme throughout very well, and most of the time it's easily recognizable, I felt like there were other times it gets buried under an assault of complexity. For instance, right away with the first variation, I'm hit with thick chords and a jaunty rhythm. Maybe that's what you were going for, but I would have eased my way into a thicker language.
On the second listen, I didn't feel that way as much. In fact, maybe hardly at all. But was it because I knew what I was looking for? It's hard to tell, but my point is, this is 30 minutes long. How many people will listen intently all the way through, then listen again to really grasp or get it. Possibly, I'm dumb lol. But that was just my impression.
Like I said though, I don't want to detract with how much I enjoyed this one. This is truly a wonderful work of art, you should be very proud. You've made me a fan of your writing, and I admire your skill in composition; it far outweighs my own.