Piano was absolutely fine. Well executed suspension around 0:04 which resolved nicely around 0:08.
Vocals were a bit thin for my taste but had this pleasant ethereal texture to it. Almost breathy/airy.
Wasn't a fan of the percussion. A bit plastic and thin for me.
The vocals jump out of this mix around 1:18 which drowns out your other sounds a bit. You always want to vocals to sit comfortably just on top of the mix.
As for the vocals themselves - nothing special but do just fine in the project.
The chordal progression is generic but that's absolutely fine considering the message/emotion you want to get across to us.
Overall, quite good - certainly pleasant to listen too. Good stuff mate!