I don't want to sounds like a prick, because I love MOCs, and giant mini figures. The problem to me is that you've built it completely from your own imagination. In most cases this would be PERFECT, however I feel that since Lego offers instructions online for free, and they have already sold giant mini figure sets, that you should follow this http://cache.lego.com/bigdownloads/buildinginstructions/4154614.pdf
and change the colour scheme. Though, I like how you've added a neck, and the Lego version does not have movable legs. You have a great starting point, and if Lego did not offer directions and a set to work from, I would like it even more, however I think with these resources you could do better.