If you want more realistic, reflective metal, you need to establish what the environment around the knight is, since metal acts like a dull mirror of sorts.  Of course, depending on the metal, you will have more or less detail in the reflected image (polished metal has a more detailed image, dull metal just reflects shapes and color).  Once you know what colors/shapes are in your reflections, then you need to figure out how to conform those shapes to the shape of your armor.  At the moment, your image is very cartoony, so I am assuming you aren't going to make this too realistic.



I've done a very quick overpainting to show you what I am talking about.  I cleaned up some of the lighting and then added another lightsource (a torch behind the knight) and a blueish floor.  The right leg (knight's left leg) is the only place I worked out any finalized detail.  I worked blue into the under sides of the metal since the floor colors would be present in any surface facing it.  I also added a rim light of orange to the rear surfaces that would be facing the torch.  This is just one approach and my sketch is pretty unrefined, so I hope you can learn something from it.  And there are also a bagillion ways to do metal, so please don't think that my approach is the only way.

Nice start so far.   

I also agree that the background should not share colors with enemies or bullets.  You might consider making explosions and bullets not share colors either.  Right now, the mockup is very difficult to read, since explosions and bullets are sharing an orange color (and the enemies have a warm color scheme that also blends into the orange).  I am assuming that if a big wave of enemies is getting mowed down, then there will be a lot of orange on orange action.  Of course, if the animation of the explosion faded off to a neutral color very quickly this might not be a problem, but I would think that changing the bullet color might be the easiest solution.

With that said, I would love to see this in action.  I love me some shmups!   

Hmmm....  thanks for the suggestions.  I am a little hesitant to make the contrast that stark (although I know that is a quickie paint job) since I tend to see early morning as having more subtle light.  I keep seeing the light (in my head) as peeking over the clouds, so only a few things in the foreground get hit directly.  But I like how you've darkened the shadows down, so I think I am going to try pushing the darks first before pushing the light to be really bright.

Also, i'm not sure if you noticed, but the colors used in the clouds actually do not share colors in the mountains or grass.  Origianlly, the clouds were much lighter, so they had unique CLUT entries.

More progress to come.

256x128  34 colors (so far)

Wanting to try my hand at illustrating with pixel art, so I made a shack... on a mountain side... above the clouds... in the early morning...

I am always struggling with color and contrast, so any C&C would be appreciated.