It's a good idea, but it's not really a new concept, as there are things like Create A Tankman and MC Scene creators which in basic terms, are effectively what this is, drag this here and change that for that. The idea of a zombie maker is (as far as I know) new to NG, but there isn't enough choice for me really in the clothes, heads and backgrounds (maybe have a partially decapitated head or something), but maybe too many eyes to choose from.
All in all the concept is good, and I do realise that you have taken time in making this (as I actually read the author's comments before writing a review) and tried your best, but all it needs really, is just more options, but no more eyes please, more than enough there! ;D
Hope I've been helpful, and good luck