Yes, I agree about there being a need for a little more contrast.
There are other ways, see, of creating focal points in an image.
There is value differences (parts being lighter/darker than other parts stand out), which has been used in these screens to good effect
Sharpness differences (god, I feel like I'm ripping off Arne's tutorial here), where something sharp stands out among blurry things, quite natural, actually, it's what the human eye does when focusing.
Color differences, of course, something that's also used here, since the girl in the pictures is the only thing in the image which has a pure red. That makes her stand out.
But there are also geometry differences. If you notice, the backgrounds are, and I don't know if that's intentional or not, mostly composed out of shapes that are either circular or square. The cacti are all circular and nice, while the viking-like environments have a lot of rectangles in them.
That makes the heroine stand out a great deal, since she is far more advanced in shape than those simple geometrical shapes, and thus, she attracts the eye in a good way.
And because of that, I think that even if she and the background had identical values, the design of the environment would still have a beneficial effect on her readability.
Just saying why darkening the dark tones on the lates screens wouldn't do a lot of harm. Heh.
