Sparkles

You need to increase the amount of contrast in between your characters. The characters don't pop out, and actually kind of blend in. An example would be the first one. The gray backdrop is very close to the skin tone of that character. The second one is the same with the white dots surrounding the character. It forces the character to metaphorically sink in and blend in. Another problem would be the lighting. It's not very clear where the light is coming from. Sure, you can tell on the face, but that's about it. On the tail there isn't any glow from the light hitting it.