Well, since this is a tonal composition for a solo instrument, I think that the piece has to imply harmony more. Sometimes I do not really know what the harmony is. This would be helped with a more clearly defined phrase structure. Also, you have to keep in mind the implied rhythmic accents of the 4/4 meter. Some times you have the phrase lead to the tonic note on the second beat, or the fourth beat, which is ok if you are doing it for an intentional effect, but the fact that you do it all the time makes me think it might not be intentional. It is also less desirable to do at the very end, the very end should be on a very strong beat, so 1. Also, if you want to create some more drama, try adding some secondary dominants! They sound really good and add some tension to the tonality. So in this case it would be E Major (dominant 7) to tonicize the dominant A Major, which would then resolve back to the tonic. You could also play something in the dominant key by using a B Major (dominant 7) to go to E Major, which would resolve to A Major. Going to the dominant makes transitioning back to the tonic key extremely easy.
Just some thoughts. Overall, nice work!