Right, some proper work, so some proper crit.

First of all, I like the textures of it, it hits me as good and it really works. My main problem with the interface is that the 'head' of the bat looks like another piece of metal just on top of the wings which have been obviously copied and reversed on themselves.

The texture is nice, but it sort of sits on the fence. You don't have full texture or have you gone for sleek. It doesn't really work too well. The white highlighted stroke on the top of the head is good, but I think it stands out too much.

The mouth is well done and really looks like a vent, you used Ax's patterns I believe, and you used it well. The blue parts on the winds are nice, but I think could do with a little more shadow behind them so they really look like they come out of the wings. The eyes like you said need more work because at the moment they look very out of place.

The one thing that really bugs me is the cracks, they are well made, but they don't seem to fit in. The face has no cracks, and it's not grungey enough to warrant them, but maybe that's just me. Another thing that I don't really like is the fact that the wings seem to get lost in the background at the tips. A thing I suggest is making a selection there, the shape of the wing and having a white gradient coming in, radial or linear and setting it on soft light or something, to make it stand out and give some relief to the bat.

Overall, not a bad WIP.