Thanks for your continued help, guys. It's all very encouraging!
I'm sorry to post yet another version with few changes to the background, but even this silly mockup took me about 3 hours of fiddling. And even so, it's just a crude mockup of what I want to accomplish. So bear with me, because I work at a very slow pace. I'm not forgetting about what's been suggested earlier in the thread.
@r1k: Cheers! What do you think?
EDIT: Now that I look at this in the light of day, I'm not happy with the scene at all. But at least it gives some indication in regards to the colours, the composition, etc. And I'll change actions and positions of the characters later.
The extremely heavy black shadows will be slimmed down, but I am rather keen to keep very dark lines and high contrast on the characters.
@Cyangmou: You may be right that there's no particular pattern in regards to the angle of the reflection lines, except the artists' desire to guide the eyes of the viewer. I hadn't considered that. It would be very disappointing.
I will try to follow your advice about reducing the contrast in the banding on background metal textures, and darken some of the above-mentioned areas of the background. I'm not sure why glass and metal always have different reflection lines. Could you explain that?
@Mathias: Are you asking for reference examples of 1980's cartoons with the style that I'm trying to imitate? Or are you asking for more screenshots? If it's the former, then I would mention Saber Rider and the Star Sheriffs, Galaxy Rangers, the Centurions... that whole genre of action cartoons.
You raise an interesting point about trying to imitate inferior art. I think that most of what I'm trying to accomplish is perfectly useful, such as going for a clean and shiny style, exaggerating the amount of reflections, or experimenting with very high saturation and high contrast. The only stylistic choice that may be a bit dubious is the addition of those reflection "bands", but I think that I'm so aware of it that there's no way I'm going to end up applying that technique to anything else. And it's a very specific technique.
@milokey: Some of what you did, I really like. The spotlights on the floor, the changes to the steel columns, the little bit of shadow on the cable. But there's one thing I somewhat disagree with / don't understand. In my mind, there are three significant light sources at play - the energy ball inside the force field, the multiple lamps somewhere above in the ceiling, and the "sun" somewhere outside to the left, illuminating the landscape and the window frames. With that in mind, I don't see how there would be any light from the dome on the walls, because the sunlight wouldn't be able to hit the dome due to the surrounding walls.
But I will try to implement the other changes you've suggested. Perhaps one of the spotlights from above could conveniently land on the kneeling character.