These pictures illustrate exactly the issue I wanted to point out. There are details in the darker areas that are being crushed into black (the first picture has more details than the second in each pair)...

Picture 1: whole left side is dark and you can't see the trees

Picture 2: bottom right corner can't see anything

Picture 3: bottom right corner, can't see the engine

Picture 4: Looks ok

Picture 5: Bottom area between the guys is to dark and can't see the details

Picture 6: Top area is too dark. Is that a guy in the upper left corner or what?

Picture 7: same as picture 6 (duplicate)?

Picture 8: Can't see details in Dark Vader ;-)

Hope this helps! Otherwise it looks great! Just boost the lower end to not crush the dark areas into black. In Adobe Levels, move the left arrow over to the right when stuff starts showing up on the curve to make the black stuff black, then move the middle arrow to the left a bit to boost the dark areas up so they aren't so dark.