This is rather... repetitive. I know you said it's meant to be easily looped, but it was a challenge to listen even for 18 seconds. You get 1 star for the fact that the instrument sound was in fact a good one.
My suggestions to you:
- make that melody longer so it will actually function as an "A section" for your music
- write a second melody to act as your "B section"
- make sure one section can lead into the other smoothly when it's looped
- pat yourself on the back for a job well done