hats are suuuuuper loud! i thought it was weird the way they sway at first but i ended up enjoying that a lot, though if they sat under the kick/snare instead of on top it'd be better. i don't think the piano reverb is an issue, actually it kinda blurs the notes out and makes them sit really nicely with the pad sound. the kick could do with some boosting, just to bring it a little bit below the snare (which is perfect btw).
the main thing with your melody is that you have very few repeated phrases at all within it, and since it's a really long melody it makes it hard to remember. you also use some strange voice leadings which clash with the underlying chords (e.g. 3m14s). my rule of thumb is if you can sing or hum it out loud it's probably a good melody. honestly if your melody and chord progression was half as long and you just repeated it twice it'd already improve things quite a lot!
overall your sound design is pretty interesting, and you've identified melodies as a weakness already. keep it up!