Like Kimon said, the number one problem with your texturing is the very blurry diffuse and the lack of material definition. But to give you any good pointers it would help a lot to see the texture flats of one of your characters. And in what engine did you render these?
Kudos for taking criticism the right way! Shows great maturity and professionalism. I think may main problem with the textures is that it feels like I'm looking at a flat, muddy diffuse. I can't really make out any spec, gloss or even normals. So I would say that the main problem is that they lack material definition.…