Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
Not bad. The only thing different is the tones of gray. Did you use a gray or did you print black? I see a smidgen of shade in the sword but very little. What line screen halftone was used? even the small shading you have, looks very fine. Maybe it was too high of a line count? Not sure.
You are learning from this one, but what would have made this more dynamic is to also include a % (10-15%) of black halftone for deeper shading on the darker parts of the gray also.
What about the fade from green to blue on the shield?I know when I played with the file I had the same issues... I used some tricks to include it but still didn't like the results... but I didn't need to print it and had to leave so I stopped playing with it.Overall it looks like a great job!
You could take your gray channel, duplicate it (gray copy) then using curves, reduce that down to only the very darkest parts. Then, you combine that "new" gray channel, with the black channel using "Calculations" under the Image menu, which will give you a new channel that has your original black and the altered gray information, putting a little shading in your grays too add depth and form. You use this new Black instead of the old black, delete that old black channel. As you move along through this stuff, you're going to find "Calculations" to be very useful.Steve