The colors and C4ds look pretty good. The things I see wrong are:
The text....its a bit too noticable, it was the first thing that caught my eye. For text small and simple are always good.You dont want your text to draw people away from the focal.
A bit Blurry......try to sharpen up some areas that you want the eyes to focus on, like the guy!! This will do 2 things...it will draw peoples eye were you want them to focus on and it will create more depth in you sigs!!
Hope this helps, keep up the great progress, your doing really good!!!