Firstly, I must say that this is fantastic work as always, my friend, But as always, Every artist has its flaws, and sadly, I must point them out.
The first flaw I see, would be the painting itself. As well as the detail looks, The water-lines are easy to see, and most 'painting' is a bit smoother with color blending if you know what I eman. It's easy to see how many colors you put in and they're poorly blended together, so they all look a bit.. strange.
I also believe that your lighting is a bit off, theres lighting in the middle, but not where the actual lights are in the painting. Also the one arm that is semi-hidden behind, It looks like its growing out of his neck, or something.. Other then a few choppy lines, this piece was very well done for your first painting