Very nice! I like that you didn't reuse any poses. It really helps give a lot of personality to each character when they have their own pose. I think the areas that could use some work is the background and the shadows on the ground. The shadows don't quite line up correctly with the feet, and the background, while it doesn't detract from the image, doesn't have the same level of polish as the characters. I think putting them in a setting and dimming the light in the background could bump up the impact of the image. An area like the Batcave, or even just the roof of a building, could look really good without drawing too much attention from the characters.