This type of style has a lot of potential, when I first looked at it it wasn't particularly grabbing but when I took a closer look I noticed that you have a pretty strong understanding of shadows and that the linework is seriously holding this piece back. I would recommend you refine this style some more, ditch the lines entirely and bring out the features and details exclusively with values as opposed to the lines, you're already practically there. The value work is especially notable on the face and jacket. I would recommend working in three tones of each color to cover the standard color, the shade and the highlight areas. I think going with that type of style would really make your art stand out from the rest as well as improve understanding of color tones and values.
Also the reflections on those sunglasses could use some work, the lights should better follow the contour of the glasses right now it looks like you're trying to get that effect but not really committing to it, pick up a pair of sunglasses and study the way the light wraps around the glass parts as well as the frames.
Hope that helped in some capacity. Good luck moving forward, man.