OK so, first things first, the quality of the playing in the recording is top notch, but sadly the quality of the recording itself leaves a lot to be desired. Too bad.
Second, I think the score needs a lot of work. It's weirdly spaced and there's a lot of stuff that needs to be removed and edited. Additionally, it would help to have clear markings when each variation starts (along with the number.) Right now everything is just glued together and it's not pretty to read. Also, the score is lacking any dynamics, even if the recording actually has them to some degree (but then again not as much as it should be, leading to the whole thing sounding sort of flat.)
And on that note, I think the musical material is handled with competence, but it lacks a great deal of the experimental nature of what variations were meant to have back in the vienna classic. Take Mozart's Variations on a Minuet by Duport, K.573 (written in 1789,) which has some pretty wild sections (the coda specially) and obviously something like Beethoven's 32 Variations in C minor (WoO 80 from 1806) really stands out as being an extreme example. In contrast, your piece is adequate in the language, but it's too safe and thus ends up feeling more like an academic exercise.
I think that this is a fundamental issue with your piece here rather than something that you can just fix. I'd advise for the next variation cycle that you take a lot more liberties, both with rhythm as well as with the register changes and tempo differences. Also, it'd be cool if you took a note from Beethoven's C minor variations and linked the variations together in a sort of overarching structure, it makes the piece that much more interesting.