I like how the background is coming along, but I think you need a lot more light than that, and, like philipptr mentioned, the rest should be even darker. It has also been mentioned before, but the gray colors in the meteor need to go. Replace them with white or yellow. I also think 174 colors are too much. Personally, I'd go for about 30 or so since there's mostly brown in the palette.
The shading on the two men makes them seem flat. The blue knight should be mostly in shadow since he's between us and the light source, and there should also be a lot more shadow on the green knight. The blood would also reflect some light.
I'd place the green knight's leg in front of the blue's since it looks very odd that he's standing next to the man he's attacking.
Their legs are malformed, too. Make their thighs the same size and shape. The blue knight also needs bigger hands.
I don't think you'd be able to see stars that close to a bright light source like that. Maybe in the other end of the image, but not that close to the meteor.
What's the orange shape at the top of the tallest tree?