what I see first, is that the paint still looks thick. Especially on the shoulders (could be from something else, but there it looks too grainy to me).
metals: I'd do a bit more shading with a dark color (even with black) to better bring out the definitions. they look good imho, if they go from almost pure black through the chosen metal color(boltgun) up to a really bright metal(silver).
clothes: be more daring, make the highlights stronger, much much stronger. Right now the cloth looks like it was based with a dark-green, then shaded with black. When highlighting the folds you could go as high as a greenish-yellow or greenish-grey (scorpion green/dead flesh)
skin: you wrote, that you used 8 different HLs on it. Sorry, but from the pictures it looks like a base+wash+1HL.
Also the grainy things in the shadow areas, that comes from drybrushing I think --> here you could get rid of them / make the shadows stronger by applying a controlled wash.
It won't give a really good transition, but I'd give a try to this for flesh (not necessarily on this figure, but on the next):
- paint it a chosen flesh color (do more layers, until homogenous)
- paint the bottom cca. 25% of each muscle group with a darker flesh color or a mix of the base + reddish brown (beasty brown) OR do a wash with a dark brown color
- if you chose the wash, then repaint the outstanding parts with the base color (correcting any spilling mistakes)
- paint the top cca 25% with a lighter color or with a mix of the base + white
- paint the top 25% of the previous layer with an even lighter color (or add more white to the previous mix)
The result is normally a clean layered painting with highlights and such, but noticeable lines between the layers. From a gaming distance it will look good though.
To get rid of those you'd need to do more mixes between the layers or learn new techinques (for example feathering / working with transparent paints). But that will up the time spent painting one figure tremendously.
of course a few questions, depending on those I'd simply stay at the look on the pictures, use what I wrote or use something more advanced (you don't need to answer here, they are for you to decide if you want to push further or stay at the level where you are):
- does the commission requires you to go beyond the quality shown?
- do you get payed enough to work twice as much or more ?
- do you want to get better and better independent of payment/requirement ?