The shading (although a little messy) and composition are great, but the vomit itself looks a little off. It looks too '2D' and doesn't appear to be going any clear direction, which is a problem with the vomit is a big part of the piece. Perhaps some more three-dimensional shading would help this, along with a little more of a pained and drunken expression from the man's face to make it seem that he is currently and lively vomiting, that or at least have him bend forward a bit more to appear as though he is bending himself to aim the already exploding puke bomb. The words inside of it were a cool, creative touch, but again, didn't really fit well with the piece's existing style. Just a bit more improvement, and this piece could be a masterpiece.
KEEP UP THE GOOD WORK, FRIEND!