The musical mix on this sounds very good, nothing but a few personal taste issues for me.
What makes this a difficult listen for me is the vocal - the pitching is a bit all over the place - at times it seems very good (in the choruses); other times it's very sour (the first few notes of each verse).
It seems it's the low notes in particular, need a lot of attention. To me, it sounds like they are a little too low for the singer's range - to be sung comfortably, at least - and the singer doesn't support them with enough air, causing the pitch to go awry. It doesn't help that the lack of breath support also causes a less-than-appealing timbre in the vocal as well.
Apart from the obvious course of tuning the vocal to the correct note, another tactic to perhaps disguise the unnatractiveness of the low vocal timbre is to make it deliberately ugly - a distorted/telephone effect or similar is probably what I would reach for.