This is a very nice piece that certainly shows a grand scheme of your talents and the way you have rendered such a creature as the hulk into a more playful, admirable concept as shown here. It certainly presents the skills you have and the way you can represent a character with such brute force into a more playful rendition through a talent that truly presents the energy and body language of the character as well. You show that you understand the character well and can reflect the body language well through your approach in drawing and the choice in cell shading. It's a style that has potentials and certainly in time will get stronger over time since you reflect a good deal of attention towards the detail and the body structure of the character at the whelm.
You have a strong talent for this style of work so keep it up.
About how long do you spend on each char?
You have a strong talent for this style of work so keep it up.