I like how the piece develops while saying grounded in the main idea ostinato. It creates some nice tension and I can see how it would keep the player on their toes the whole time.
One thing that bugs me though, are the long notes on flute at around 1:50~2:20.
It's not that much of an issue on the bassoon because of the register (I guess), but on the flute in wears out my ears a bit too much. Some breathing space would be nice.
But it's a great composition anyway!