I just think its too overworked for a logo with the 'underground thing.' You already have windows, a front door, a cross on the roof, attic windows... All your missing is a chimney and a back garden. Sorry I don't mean to be rude, I just think it needs to be dumbed down and with the 'underground' it is just going too far. The more you work into this, is the less it will look like a logo. Any more and it will just look like a drawing next to some text. Again, I apologise, I know how difficult these things are and I really like your ideas, it just needs a final tweak for it to be complete.