Feedback on rejected piano music

Hello fellow authors,

I’m new to music production and audiojungle so I know there is still a lot to learn, especially with mixing etc. However, I wrote a pretty simple piano waltz, for which I thought was nothing special, but ok enough to get accepted. It got rejected and I would really appreciate feedback from you. Thanks in advance!
https://soundcloud.com/user-305555493/classical-piano-waltz-watermark