I really like your art style in this illustration. It looks graffiti like and I find it very appealing. However, what I really don't like about it is whatever is going on with the skull's jaw. My guess is that you made it look like it's jaw is melted or deformed or something, but nonetheless, it doesn't look very alluring.
If you ever have the time or think this illustration is worth redoing, I would recommend actually drawing it with a jaw and teeth like how a skull should look like. It would look far better that way, in my opinion, and I think others would think the same. I would love seeing it redone, but that's your call.
Overall, very good effort, but how you made the skull's jaw look really killed this piece of art for me.