Quite a lot, actually, but mostly in the harmony! I really like the harmonic progression in mm. 12-17; how it flirts with very distant keys but stays grounded, returning to the opening melody before it gets too far astray. In terms of phrase structure, it's also a really nice little interruption, kind of like our thoughts are straying from the main melody just enough to make it interesting when it comes back.
Maybe I should rephrase my previous post, too. I think it just helps to be aware of the little quirks like these that make your sound unique, and do them deliberately--you don't necessarily need to make those things the focus of a composition.
And it might be just my own strange ear that was reminded of Chopin at some points in this piece (especially the opening/main melody). There are worse composers to inadvertently sound a bit like!