It didn't strike me as sloppy playing at all; I thought it was a excellent performance. From a composition standpoint, my only advice would be to let the music breathe a little, if that makes sense. There are several good ideas that sometimes seem to run into one another fighting for attention. That's just a minor critique. For writing this at such a young age, I have to say well done, and keep up the good work. At 12 years old I was sitting around the house playing Super Mario Bros.