I really enjoyed your piece. I had a listen to your performance and had the opportunity to follow through the score.
I'd like to talk about the form you used. Most sonatinas have a sonata form, the ideas are simply in smaller proportion. And usually have several movements, you did that, so that's good. When we talk about the first piece,
generally it's written:
I: Exposition :I: Development I Recapitulation :I
This is of course a general guideline, not a strict rule. And even though you have no repeats, I think this piece works in through-composed form, with some exceptions.
You clearly have a repeated exposition, I hear the beginning for two counts. in m.1 and m. 15. if I'm counting sixteenths, it sounds like "da-dada-da-da-da-daaadadada" (with a hyphen counting for 16th rests)
You have the development shaped well, it's just that we never hear the return of the "da-dada-da-da-da-daaadadada" !
Let me tell you a story. This was this last year at the beginning of the semester. I told my piano teacher that I composed a piece. She said, "great! Do you have a name for it?" I told her it was called "sonatina." She told me it didn't have the proper form (of course she would know, she is a piano teacher!)
so now I am passing this information on to you!
If you want my advice, you can either fix the piece to adhere to the proper sonatina form, or change the name of the work to "preludes" (that's easy enough, huh
Hope this helps and really enjoyed your piece.