Help me understand why the track was rejected

I ask the authors for advice on why the track does not pass (it is not the first one).
I don’t understand what exactly it is worth paying attention to.
What is worth working on more: arrangement or harmony, or mixing, or mastering?

Please give advice

In my opinion, the music composition is good, but in the balancing part it is still too mono, maybe in the future you can mix a track so that it sounds wide and stereo.

thanks, will try