concerning the instrumental part, i like the drums, and the melody, but i would thicken things up if i were you, especially in the chorus. like, it always has me wondering what's missing. it ain't that hard, there is not a lot missing, but some little things can make it a lot better. and some instruments... like the one we hear at the beginning, and especially the one we hear all the time... it's probably a xylophone or something like that... i would change them... they don't sound very real. of course if you do what i said earlier, by adding more instruments and tracks, it covers the other instruments, and you hear only what's essential.
the mc is really good, he's got a good voice and flow, really commercial. i wouldn't ask myself why if he was a mainstream rapper.
the girl sings well, but i don't know... i would add a lot to the chorus. it's not as strong as the rest of the song, and usually the chorus should be the strongest part in my opinion.
of course i notice more what i don't like, therefore my comments are mostly negative. but i think the tracks sounds pretty good, and i hope you keep working on it