First of all - thank you for showing the sheet music. I love videos of pieces with the sheet music, it really helps me listen to it more thoroughly.
The main theme is, in my opinion, prefect for this context - very folky, pretty catchy, and not too bright or dark.
I also like the juxtaposition of the very fast melody that comes right after the folky tune, though I would perhaps make it a bit slower (maybe 16th notes instead of 32nd?).
The flying part is also has a nice juxtaposition with the first part, and is very fitting. It's chaotic nature seems intentional (it's really stravinsky-like), and I think it definitely works, but if you intend to continue to work on this piece, I would maybe work on it to make it feel a bit more cohesive, while still keeping the chaos in it.
The last theme being the first one is really nice, and it helps the classical feel of this piece, in having this ABA structure.
Great piece, good work!