Review of Waltz in f minor:
Melody:
I love the charming, simple melody you have in the foreground. However...as a listener, it is bit repetitive. You have established basic idea from the start well. But, you need contrast against. The audience needs to go "awe" and be able to listen piece from start to finish. This is why we have melodic form and structure. It just needs to flow logically and have contrast. Furthermore, you don't normally see that rhythm pattern in waltz. It nice to hear something different, but it makes us wonder is this a waltz or something else. Reconsider that. At m. 21, those 16th might be too difficult for pianist to perform. I know you were trying use what chopin what would have use, but he was very talented, and pianist today...their hands hurt. Trust me.
Harmony:
through out the entire piece, the harmony does not adventure too far away from key. (i.e. mainly diatonic). I feel that it would be better if there were chromatism with harmony and the piece modulates.
Form:
I am not sure what form is...