You could make a hanging-man(and hanging-woman!) sprite for every skin-tone group on Earth, so nobody will think that your penchant for grim and violent imagery is unfairly focused.

On an Actually Useful Note, the purple guy doesn't fit with the other three so well (I think it is because he is bigger and has brighter softer-looking light/colors). =) Considered individually I like them very much but together they don't seem cohesive.