Well for a sketch is something complete by itself.
First of all, I don't believe that music can describe anything. I do believe music can transmit emotions and sensations and you can take a story as inspiration.
There are many good ideas in the sketch. At first I thought it would be a bit boring because of the vertical chords (wich is a way to underuse the piano), but as an introduction is perfect for what comes next. The allegro speranzoso part is wonderful, simple but fantastic (I would take this part to develop, it's between impresionistic and minimal). The third part is OK because the chords are emphasized and tha left hand is different. The frenetico part is the one I understand less in the piece... The largo part is good, a strange chord here (F - Ab - B - C), this is used in some oriental scales. The last parts include new motives... And that's a "problem"... many parts with many possibilities...
When there is much material in a short time is like a musical brainstorm. Yes, I know it's a sketch and it's supposed to be written quickly. Anyway I always, in my case, try to put some order in everything I do (even using simple forms like AB, ABA, ABAB).
Greetings!