Really great sound design imho, but there are some problems.
First and foremost, I’d say that instrumentation is a problem, and from the admittedly cursory amount of your previous songs I’ve heard, instrumentation seems to have been a consistent problem. Personally, this is how I think of instrumentation:
At minimum, one low element, one mid element, and one high element; at maximum, (roughly) one element per octave. Kick, snare, and other such primary rhythmic elements are always exempt.
...except by now, you ought to know that rules are made to be broken, haha. This rule tends to be broken in buildups, where a lack of bass could be used as a tool to give the song a bit more tension (though this rule is broken only when tasteful, of course). This rule could also be broken in intros and outros, to more gracefully enter and exit the listener’s awareness, I guess.
In all of this, you should focus on the fundamental pitch of any instrument when determining what range category it falls into. What I mean is, for example, if you have a piano part, you should use the fundamental pitches of the notes to determine whether you should count it as a low mid part or a high mid part (maybe both!). An example of a good time to break this rule would be if there happens to be a vocal part that you want to really “pop.” In that case, you can count it as both a mid AND a high element, to better account for higher harmonics, sibilance (S’s, T’s, etc.), and breath that you may want to highlight.
Just keep it tasteful, lol.
Secondly - yes I know this is an absolute novel - mixing. Different people will say different things about the overall goal of mixing, but as a producer, I think the most workable/tangible goal of mixing is to make each element’s presence match its importance. Yes, those are ambiguous, and yes, that will often require interpretation, but hey, that’s what’ll make your music unique, right? Here are some examples of these concepts:
Things that affect presence:
Things that are typically important:
Things that are typically not so important:
Importance is more subjective than presence. Importance wholly depends on what YOU want the song to be, whereas presence is simply the technical nuts-and-bolts of getting the mix to reflect your view of each element’s importance.
That’s all I got. Hopefully this helps some!