I saw this as a thumbnail and I really had to check it out. Its even better than I thought when I saw the thumbnail. I like the feet and spine positioning. and especially the motion on the heart exploding out (however grotseque that may be lol).
there are some things you should practice, such as hair shading, body shading (the arms and hair), anatomy (some things are out of proportion) and the red myst looks like it needs either a smoother or more intense and noticeable transition.
Overall, I think you did pretty good and it's nothing that practice can't improve, so keep it up