Great work!
The detail of the illustration is phenomenal. I can see that a lot of time and planning went into this. The composition works well and the typography doesn't distract from the overall illustration. So, great work! My only criticism is the standing figure in the center's anatomy seems odd. The perspective doesn't work here. The figure is too frontal. The "camera" should be angled more downward on him-- this way, his torso and lower body will flow better.