Your composition needs some improvements overall:
- turn down the e-piano and the synths
- put some more bass on the main kick-ish(?) sound, but don't overdo it
- use subtle effects for transitioning to the next changes in the song
- turn down the overall volume of the mix and/or look at your master limiter
- to make the explosion effect near the end hit better, like i said, look at the your overall dynamics of the song (-> limiter on master track)

but i have to say that
- once the song builds up a bit, i like the overall installment quite much
- the harmony and everything fits
- the choice of instruments is good
- hec, you even included voice samples.

good job for your first published thing.