This is one of my favorites so far. It's interesting to see the group gathered around the game. Shallow DoF helps to focus on the card player. My favorite thing about it is the eye contact from the one individual. That connects the viewer to the scene.
This is a good street shot, in my opinion. You've got a lot of interesting characters, a good setting, a bit of a story going on. There's even lunch sitting on the bench, apparently forgotten because the game takes precedence. And at least one person appears to have caught you. :-)
I like that the guy in the cap looking at the camera. It adds interest to the shot. A b/w treatment may even make this a stronger shot by removing the distractions of color throughout the image.