Hey Yorgo,
The two biggest things for me were the lack of low end on the kick and the piano in the chorus. The kick has a nice sounding smack, but no real thud at all. Compare that to your tom, which carries some weight. The kick frequently is completely lost when the song is not in one of the sparser sections. Even when the kick is given room, it just lacks authority due to the lack of low end.
In terms of the piano, the timing seems a touch off (frequently a touch too soon, this is most noticeable in the second note of the third couplet), and overall it just pokes out a touch too much. It also seems like there are maybe some slight tuning issues between the piano and the rest of the instrumentation here, but that also could be due to which frequencies are being emphasized due to eq.
The other thing is some slight tightening of the vocal layers in terms of the timing in the chorus in particular would help. The starts and ends of some of the words in a few places are too different, so it undermines the effect you're going for.