I can see what you’re trying to do (I think), but I dont think you’ve quite nailed it. If I was to take this myself, I’d use a combination of shallow DOF focusing on the homeless/drunk guy and perhaps a longer shutter speed to blur the movement of the people as they walked by! As it is, it just looks a little busy & to echo Mark’s comment, the noise doesn’t add anything to the colour version.
Gonna have to echo the comment about the noise. It really dosn’t suit unless it was black and white. (Which could really suit the image, considering the pattern of the tiles)
There’s a great idea behind it, but an extra few mins there, or in photoshop could make it that bit better!