The drawing itself is good, nice hands. Though the eye that can be seen on the right character is too high. Eyes tend to be roughly halfway down the head.
Mostly my comments are about the colouring. The lines are very light compared to the colours, which looks odd, and there are many white specks where you didn't colour in some small places. Also you sort of go overboard with the gradients and lens flares.
Looking through your gallery at some of your other Photoshop coloured pictures, it looks like you are laying colour down on top of scanned pencil drawings?
If you want a much cleaner look to your drawings, here are some ways you may want to consider CGing your pencil drawings. They are more time consuming than how you are doing it now, but you may want to give one of these a try.
You can either start with a pencil drawing and ink it digitally, or hand ink your drawing and scan it that way. If you start with an inked drawing, here is a good tutorial for colouring it:
Julie's TutorialWhat I do is start with a pencil drawing. I scan it at a large resolution because I like to work big! Working large is good for two reasons: you can fit more detail in, and when you resize it for use on the web, it makes your lines look more smooth.
Once I have my pencil drawing in Photoshop, I create a new layer and call it 'line' where I do all of my inking. I like to ink with the smallest airbrush set to 50% pressure. I go over a pencil line several times until I like how dark and thick the line is.
Once I have my lines finished, I make new layers (careful to put them under my line layer) and colour on those. Generally I use a lot of different layers. For hair I have a layer for base colour, another one for shading/lowlights, and another one for highlights. I tend to have several layers devoted to each seperate part of the picture.
For now, just lay down the base colours and don't worry about shading. Make sure all of the colours look good together. Then pick a light source before you begin shading. You have to know where the light is coming from to know where the highlights and shadows are, and to keep them consistant throughout your picture.
Well, this has come out longer than I ment it to. Let me know if you have any questions about what I've said.